Jumping in to Apple 1 scene

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Jumping in to Apple 1 scene

Hi,

I've been thinking about it for a while, and now the stars have lined up for me to try an Apple 1 replica build. My interests are to get reaquainted with the Apple 1 stuff, and to try out some 6502 machine coding. It looks like the currently available options are:

1)  RetroTechLyfe board/kit

Pros: ?

Cons: Keyboard and Video I/O is thru USB to laptop terminal emulator only. No 44-pin conector for cassette or other possibilities.

2) Latest Briel / ReactiveMicro Replica-1

Pros: Has local Video Output. Keyboard can be parallel ascii, PS/2, or USB to laptop computer. Has 44-pin connector. Board has room for some hardware hacking.

Cons: ?

3) Full Size Apple 1 replica board from eBay with component kit from Uncle Bernie

Pros: Best look and authenticity. Tempting because I have a personal interest in the shift register video circuit (Why that is will have to wait for another day)

Cons: Assuming I do all the Uncle Bernie reliability mods, will it be reliable enough for software development purposes? Also, total cost to get running is uncertain.

 

What is the opinion of the board on the best way to get started?

Thanks in advance for your opinions.

Jeff

 

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About the reliability of Apple-1 clones ...

In post #1, "jmmh" asks:

 

"will it be reliable enough for software development purposes? Also, total cost to get running is uncertain."

 

Uncle Bernie answers:

 

Yes, if you do a proper soldering job and if you use good IC sockets, and my kit, it will be reliable. My burn-in machines run for one month 24/7 and no crash is accepted, ever. If a machine crashes, I substitute the usual suspects (ICs) and restart. With the current kits using Intersil DRAMs most builders just need the 390 Ohm damping resistors to get a reliable, robustly running build. I have one builder right now who is struggling with DRAM problems despite the six resistors are in. But the extra capacitors are not in yet. This is because we try to figure out what really is the root cause. But in the end, every builder who accepted my coaching on my hotline has ended up with a build that runs rock-solid. It also seems that with the Gen2 improved ACI the last huge problem with the Apple-1 has been rectified.

 

Pricewise, you can send me a personal message (click on "send PM") for the price of a kit I sell directly, too. On Ebay there often are bidding wars, which I hate, but I simply can't do "Buy it now". If I did that, speculators would snatch the kits away as soon as they are listed and then turn around and sell them at a higher price. This has happend with my early offerings for core IC sets, PROM sets, etc., and I hate that even more than the bidding wars. These speculators are professionals who are after a quick profit but they don't want to invest the time needed for winning an auction. By using auctions, everybody, even those from overseas who sleep when I would list, have a fair chance.

 

If you live in the USA and go with Triad F31-X and F40-X transformers from Mouser and the big blue Sprague capacitors, which are available from Mouser (they have the 5300u/15V in stock at the moment) and Digikey (they have the 2400uF/25V), you need ~$150-$170 more (additional to the price of my kit) until you have all the parts together. It depends also on which IC sockets you use (the machined contact ones are more expensive). The motherboard PCB will cost you another $50 to $120 depending on which one you buy. ACI PCB you can get from me (but they are running out). So in the end you will have paid $500 ... $666.66 until you have a fully populated Apple-1 and ACI card. And then you need a B&W monitor and a keyboard. If you need to buy those we are looking at about one grand for a complete system. (You may now see why Vince Briel's Replica-1 is so attractive for those on a budget). There are ways to save money, i.e. building my keyboard emulator cable, but then you need an old notebook or so running DOS and having a DB-25 printer port. These used to be super cheap, nobody wanted them, I bought a few for $10 each at garage sales or flea markets, but now the prices for those on Ebay have exploded. It seems that there are lots of legacy machines out there which talk to the PC via the LPT port and now companies or individuals who have to keep these machines running have started to hoard such old laptops and notebooks and drive the prices up. There also are various PS2 to Apple-1 keyboard adapters for around $50. The irony with them is that the microcontroller on them may have more compute horsepower than the Apple-1 itself ...

 

The cheapest way to develop software for the Apple-1 is to use the POM1 emulator and the atasm assembler under Linux. Both are free / open source. I use them myself despite I have written my own Apple-1 emulator (which is exact but 10x slower than the real Apple-1). This does not mean POM1 is bad, no. But its 6502 and 6820 emulation is nowhere near where it should be. However, as long as you don't use decimal mode, and only the "official" NMOS 6502 instructions, and as long as you code the I/O routines as shown on the Apple-1 manual, your program developed on the POM1 will work on the real machine. Try a few tricks which deviate from these rules, and it probably won't work on the real machine. I have lost a lot of time to these inaccuracies. The keyboard handshake being the main trap, but the output to the terminal section can also lead to a pitfall if you deviate from the "right way" as shown in the source code of Wozmon.

 

I don't think it's viable to develop software on the Apple-1 itself. The editing capabilities are so limited (there is no backspace, and no on-screen editor) that it quickly gets frustrating, even when using BASIC. This means you need a Linux (or, at least, a DOS) machine as a cross-assembler host and software developing platform. I've never tried to compile atasm for DOS, though.

 

So building an Apple-1 clone is not cheap. The emulator solution is the cheapest unless you have to buy the modern PC/Notebook to run Linux on. The Replica-1 is the most economical solution with modern ICs and with the Gen2 improved ACI it finally has a cassette interface that works with it. As I only have Apple-1 clones (fourteen in total right now) I'm of course not inclined to use any of these replicas or or other simulacrums based on modern ICs myself. So I don't know if the latter give you the same magic feeling the Apple-1 clone (using the original circuits) can produce. If hidden in a wooden enclosure, the Replica-1 can pretend to be the real McCoy - but only for so long. After a short while the onlookers want to see the PCB - and then the illusion vanishes.

 

In the whole Apple-1 clone scene there are a lot of weird psychological effects at work. Much  more than with any other vintage microcomputer. These effects defy rationality, reason and logic. Enough for some people to spend a lot of money on building one. Similar psychological effects do exist for other elusive vintage microcomputers, like the Sinclair Mk14 or the Kim-1. Or the Nascom. Or whatever is your favourite. I've been in this vintage computer scene since its beginning and I have observed a lot of attempts with reproductions of said machines using modern ICs. Most of these reproductions were not real clones in the sense of "look and feel". They deviated from the originals, most often in the key switches or other subtle details. And I got the impression that none of these less faithful simulacra ever became popular. The Apple-1 seems to be the only example where the popularity of a clone of a vintage microcomputer exceeds the number of originals sold. As my best estimate, there are about 600-700 Apple-1 clones in the world right now. However, most of them are wall hangers despite they would work. I don't know how many Apple-1 clone owners actually  use  their machines. 20 ? 30 ? 50 ? Worldwide ? I have no idea how many.  But I don't think the numbers exceed 50. So this is the "audience" for Apple-1 software developers.

Which explains a lot. It's a pity, because IMHO, the Apple-1 is the most honest and satisfying microcomputer for programmers there is: you have to code everything yourself, except maybe the ECHO subroutine in the Wozmon, which outputs a character. There ain't no subroutine to query the keyboard. All DIY. Which is the test for real programmers: if you can program the Apple-1 using 6502 assembler, you can do anything, with any microprocessor or microcontroller.

- Uncle Bernie

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Having just done this (have a

Having just done this (have a look at my thread)

 

I would say, get the kit from Uncle Bernie 

Get the PCB from apple1replica on Ebay as I know these work

Get an Apple ][ keyboard and an Apple Encoder ][ plus (got both of these from Apple2PlusParts and the encoder works perfectly with the A1)

Brand new F40-X & F31-X transformers from Mouser

Stamped pin sockets from Mouser

Big blue Caps from Mouser and/or digikey (in stock now, so if serious order them now as they take a few months to make once they are out of stock)

 

It all adds up to quite a cost but it works and its fun to do. Mine is completley stable so far with no mods at all and is as close as you are likely to come to the real thing without getting really obsessive about date codes etc 

 

Any questions about my adventure, feel free to ask.

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It sounds like a full size

It sounds like a full size one would be ideal for your long term goals, but I will say the briel is great for your short term goals of trying out the 6502 machine coding.

 

So I suppose your budget is the big variable. If it's not an issue, then start your venture and get an Uncle Bernie kit while you still can. If you're being more frugal in the short term I will say that the Briel is really fun. I have used it with @P-LAB 's micro SD card as well as Uncle Bernie's new improved cassette interface. In doing so I have learned a lot about the machine even just having the Briel replica myself. 

 

I also strongly recommend the high quality reproduced manuals available, I am quite fond of my copies. https://www.apple-1-replica.com/shop/Apple-1-Manual-Collection-p380183773

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Hi,Based on everyone's

Hi,

Based on everyone's comments, I am in PM discussions with Bernie about getting a component kit from him.

I will keep you posted!!

Jeff

 

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 For reference, this is my

 

For reference, this is my order with Mouser for the bits I needed to add to the kit. I did order the wrong (narrow) 24 pin socket but have amended that in the order below.

The last two capacitors were stop gaps until the big blues turned up

 

Oh, and you will need some thermal past for the heat sink mounting.

 

ctProduct Detail Customer NoOrder Qty.Price (GBP)Ext. (GBP)

Status

Date

Invoice No.

 

Mouser No:

553-F-31X

Mfr. No:

F-31X

Desc.:

Power Transformers Power Transformers POWER XFMR 10.0Vct@3.0A 115V CHASSIS MOUNT w/LEADS

  1£14.42£14.42 
 

Mouser No:

553-F40X

Mfr. No:

F-40X

Desc.:

Power Transformers Power Transformers POWER XFMR 26.8Vct@1.0A 115V CHASSIS MOUNT w/LEADS

  1£12.46£12.46 
 

Mouser No:

75-39D538G015JP6

Mfr. No:

39D538G015JP6

Desc.:

Aluminium Electrolytic Capacitors - Axial Leaded Aluminium Electrolytic Capacitors - Axial Leaded 5300UF 15V

  1£13.83£0.00 
 

Mouser No:

75-39D248G025JL6

Mfr. No:

39D248G025JL6

Desc.:

Aluminium Electrolytic Capacitors - Axial Leaded Aluminium Electrolytic Capacitors - Axial Leaded 2400uF 25volts

  2£13.20£0.00 
 

Mouser No:

567-680-125A

Mfr. No:

680-125A

Desc.:

Heat Sinks Heat Sinks Maximum Efficiency, Omnidirectional Heat Sink for TO-3, 31.8mm Height

  1£10.93£10.93 
 

Mouser No:

649-DILB8P223TLF

Mfr. No:

DILB8P-223TLF

Desc.:

IC & Component Sockets IC & Component Sockets 8P IC SOCKET

  1£0.16£0.16 
 

Mouser No:

649-DILB16P-223TLF

Mfr. No:

DILB16P-223TLF

Desc.:

IC & Component Sockets IC & Component Sockets 16P SOCKET

  42£0.207£8.69 
 

Mouser No:

649-DILB14P-223TLF

Mfr. No:

DILB14P-223TLF

Desc.:

IC & Component Sockets IC & Component Sockets 14P DIP SOCKET

  12£0.171£2.05 
 

Mouser No:

649-DILB24P-223TLF

Mfr. No:

DILB24P-223TLF

Desc.:

IC & Component Sockets IC & Component Sockets 24 POS DIP SOCKET

  2£0.352£0.70 
 

Mouser No:

649-DILB40P223TLF

Mfr. No:

DILB40P-223TLF

Desc.:

IC & Component Sockets IC & Component Sockets 40P DIP SOCKET STAMPED AND FORMED

  2£0.558£1.12 
 

Mouser No:

712-CONBNC004

Mfr. No:

CONBNC004

Desc.:

RF Connectors / Coaxial Connectors RF Connectors / Coaxial Connectors BNC Connector Jack, Female Socket 50 Ohm Bulkhead Mount, Solder Pot

  1£1.99£1.99 
 

Mouser No:

611-CN202J3RS215Q7

Mfr. No:

CN202J3RS215Q7

Desc.:

Rocker Switches Rocker Switches DPST 16A ON-OFF RED

  1£3.60£3.60 
 

Mouser No:

661-ELBK250E532AM20S

Mfr. No:

ELBK250ELL532AM20S

Desc.:

Aluminium Electrolytic Capacitors - Radial Leaded Aluminium Electrolytic Capacitors - Radial Leaded 25V 5300uF +30% Tol. AEC-Q200

  1£2.77£2.77 
 

Mouser No:

661-ELBK350E252AL20S

Mfr. No:

ELBK350ELL252AL20S

Desc.:

Aluminium Electrolytic Capacitors - Radial Leaded Aluminium Electrolytic Capacitors - Radial Leaded 35V 2500uF +30% Tol. AEC-Q200

  2£2.56£5.12 
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Current situation with Apple-1 parts at Mouser and Digikey

To amend the list of GaryC in the previous post, this is the parts situation of a few days ago:

 

www.mouser.com:

39D538G015JP6 25.7 x 67.1 5300uF 15V  155 in stock 7/18/22

39D248G025JL6 25.7 x 54.4 2400uF 25V    0 in stock - back in October, here a viable substitute, slightly smaller diameter:53D222G063HL6 22.5 x 54.4 2200uF 63V   66 in stock 7/18/22

 

www.digikey.com:39D248G025JL6 25.7 x 54.4 2400uF 25V  165 in stock 7/18/22

 

So you can indeed get the correct big blue Sprague capacitors right now, no stopgap solutions needed, if you are willing to order at two different distributors.

 

Mouser also has the correct earless 44-pin connector in stock, although with a price I can't accept for my kits ... I used to pay half that 3 years ago for the same connectors:

 

EDAC 305-044-521-201, Mouser # 587-305-044-521-201, $10.57 @ qty 1, in stock as of 7/26/22: 18 pcs

 

Mouser has much poorer quantity discounts compared to Digikey. When Digikey had all the big blue Sprague capacitors, the sweet spot was qty 25 and you could get the set of three for below $50 if bought in quantity. These good times are over. Prices exploding everywhere. I just paid $60 for two small 100% grass fed beef filet steaks at Whole Paycheck. Madness ! --- oh, and please don't eat the cheap meat, really. The cheap meat is produced in a sort of cruel animal concentration camp with unbearable stink - when I fly a plane to Lamar/CO I have to fly the approach over one of those and I nearly have to puke, despite still being high enough that those cattle look like ants. They feed them toxic glyphosate tainted GMO corn. You can taste all the abuse in the steak. It's probably toxic, too. You don't want to eat that crap. But I digress ... back to the Apple-1.

 

The cheaper heatsink is the Aavid 568303B00000G and it has the same thermal performance as the Wakefield, only the conformity on top of the cooling fingers is less perfect on the Aavid. Barely noticable. Both Mouser and Digikey have plenty in stock at the time of this writing, but Digikey has the better price.

 

So you can see that all components not in my kits are readily available from new, current production. It's amazing that these big blue Sprague capacitors are still being made, for more than half a century now. They are still "Made in the USA". Unbelievable, but true.

 

About the transformers, the Triad F31-X and F40-X are very close to the super expensive (but still available) Stancor brand transformers, but these are 110Vac only. I wonder how GaryC (from the UK) handles this discrepancy. It's not difficult because suitable step down transformers 220Vac/110Vac can be bought for below $50 and at these low power levels, the difference in line frequencies does not really matter. For EU builders there are alternative transformers available from Conrad electronics, I was told.

 

You might ask yourself why I don't supply these components in my kits. It's about my mission objective (to provide the critical parts which are hard to get) and about economics, too. If I buy them for you to put them into the kits I have to pay shipping and sales tax, then add the usurious Ebay fees, and then Ebay adds sales tax again, and all these skims quickly add up to ~30% and more and at the moment the economies of scale (buying parts in larger quantities at a discounted price) can't compensate for that anymore, so if I'd put them in the kits, you have to pay more in the end, and I have more work. Makes no sense.

 

So have no fear - the "missing" parts not in my kits are readily available and under normal circumstances (before the wannabe tyrants sabotaged the economy with their insane and totalitarian but uttelery useless lockdowns) they all were in stock and usually never ran out of stock. With the current supply chain chaos it's more work to find them but it's doable. The downside is that instead of ordering from one source you may have to order from several sources, and maybe you have to wait for a few parts, but stopgap solutions are plenty and cheap.

 

So far my 10 cents on parts procurement. Have no fear ! And get 'em before the GTP becomes totally worthless. When a loaf of bread is $100 we won't build Apple-1 clones anymore. Have fun as long as it lasts !

 

- Uncle Bernie

 

 

 

 

 

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UncleBernie wrote:I wonder
UncleBernie wrote:

I wonder how GaryC (from the UK) handles this discrepancy. It's not difficult because suitable step down transformers 220Vac/110Vac can be bought for below $50 and at these low power levels, the difference in line frequencies does not really matter

 

As I also have two Microvax 3300's that I got from work which were 110V (we use 110V in the UK for industrial sites as 55V centre tapped supplies are safer) so I already had a 240/110V transformer :)

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Hi Folks, my main board and

Hi Folks, my main board and parts kit from Uncle Bernie arrived today, and everything looks great. This is a great time saver and worth every penny. 

Jeff

 

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Great ! I would leave

Great !

 

I would leave everything wrapped and boxed until you have collected all the parts you need.

 

Have you decided on case/mounting and transformers ? You are also in luck as the big blues are available from Mouser and digikey at the moment.

 

The first thing I did was make a baseboard to mount everything on. Reduces the chance of accidents and allows easier testing of the mains wiring.

 

NOTE - the oneshot IC has the relevant resistors packed with it, so make sure they stay together (can't remember the number)

 

The stamped pin IC sockets are the easiest to use as you can bend over the legs in opposite corners to hold them in place when you turn over the board to solder.

 

Take your time. Its worth doing everything properly, so don't bodge somthing if you dont have the part. 

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Placed my Mouser order today.

Placed my Mouser order today. Pretty much the same as recommended by Gary, except that the 8 pin IC sockets, you need to buy 9 not 1. On the capacitor front, they had the 5300 uF in stock, so I ordered that, but the 2400 uF are still out of stock. 

Jeff

 

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Digikey have the 2400uf's in

Digikey have the 2400uf's in stock.

 

https://www.digikey.com/en/products/detail/vishay-sprague/39D248G025JL6/5610213

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Hi jmmh!

Actually you need only one 8 pin ic sockets on D13. In the other places where 2x8 pins (D4, D5, D14 and C11) they usually put 16 pins.

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Macintosh_nik wrote:Actually
Macintosh_nik wrote:

Actually you need only one 8 pin ic sockets on D13. In the other places where 2x8 pins (D4, D5, D14 and C11) they usually put 16 pins.

 

 

I thought he was making the point that mousers minimum order was 9 rather than 1 which is odd because I managed it.

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Hi,I made my order based on

Hi,

I made my order based on counting the package outlines on the pcb. I didn't catch that it is set up for 16 pin socket in place of a pair of 8 pins. I'll decide which option once I have the sockets in hand.

Jeff

P.S. I just got home from VCF West where I saw the broken half of the 'first' Apple-1, and I had a nice 20 minute conversation with Liza Loop.

 

 

 

 

 

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Progress Report - 555 Timer working

Hi,

 

Here is the progress on my Apple-1 build. Test conditions: All passive components installed, power supply components installed and tested, plugged in just one I.C., the 555 timer. I chose this for my first test since it has no dependencies on anything else on the board. Results of test: The 555 timer is working!  Later, this square wave will be used to control the blinking of the @ sign cursor character.

 

 

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jmmh wrote:Hi, Here is the
jmmh wrote:

Hi,

 

Here is the progress on my Apple-1 build. Test conditions: All passive components installed, power supply components installed and tested, plugged in just one I.C., the 555 timer. I chose this for my first test since it has no dependencies on anything else on the board. Results of test: The 555 timer is working!  Later, this square wave will be used to control t

 

 

:)

 

Are you going to do a full build thread, every detailed step :)

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I'll just show a few photos along the way

Hi Gary,

I think I'll just show a few photos along the way, then a summary at the end.

 

Here is the next test, with all TTLs installed. None of the hard-to-get parts have been installed yet. This is the expected results, when the 2513 character ROM is not present.

 

 

 

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Lots of @ signs

Next test: All TTL's installed, plus the 2513 character ROM only. Since the 2519 is absent, the 2513 receives all zeroes via the 7.5K pulldowns. All zeroes is the 6-bit ascii code for @ sign.

 

 

 

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Looking good.

Looking good.

 

Have you decided on the keyboard yet ?

If you go Apple ][ then the ⌘ Encoder ][ Plus to replace the standard external encoder is highly reccommended.

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Holy Grail of Apple-1 Construction?

Hi Everybody,

I couldn't think of another incremental test, so I decided to jump right to the end. All I.C.s installed except for the 2nd bank of RAM. Connect to a vintage monitor. Power Up. Press Clear Screen button. Press Reset Button.

\

@

 

Jeff.

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A note on first power up of an Apple-1

Hi Jeff -

 

I appreciate your detailed report on building an Apple-1 (apparently using one of my IC kits) but I don't understand why you complicate the power up process needlessly. Here is what my "Tips & Tricks" pdf every buyer of my kits gets advises:

 

a) first power up with empty IC sockets. Check all regulated voltages to be in spec.

 

b) 2nd power up with ALL sockets populated.

 

Every other procedure attempting to "protect precious rare ICs" is pointless. Once the regulated voltages are known to be good, put 'em all in. "All in" like on the Craps table in Las Vegas ... no, just joking. But you get the point.

 

There is only one precaution to be observed ... if any power up of an Apple-1 produces anything else than the expected random character patterns, shut off the power immediately.  I have to go through this ordeal for every kit I make four times, once for every row of ICs, and I can tell you that sh*t happens and if you don't shut off the power immediately if something is wrong, some IC may melt its socket.

 

But with my 100% tested and burned-in IC kits this won't happen. I did that for you, and all the offenders went to the "IC graveyard" on top of my monitor, see the photo in post #14 of this thread:

 

https://www.applefritter.com/content/horror-room-symptoms-bad-cis

 

Next Helloween I will post another photo of the "graveyard" as it is now. You will be shocked. This is why making Apple-1 kits is not really commercially viable. Messing around with 40+ years old "new-old-stock" ICs comes with a high rate of casualties. If you don't test them, your disappointed and angry customers will ring the phone of the hook and make death threats. If you test them, you put so much RQLT in it than even $1000 for one IC kit would not compensate for the RQLT.

 

I decided to do this terrible and unrewarding work because I need a statistical basis for my claim to fame that I am "The guy who fixed the Apple-1 (tm)". To show the Woz how it could have been, back in the day. Money wise I'm still in a sea of red, but for me, money does not matter anymore, due to age. You can only eat and drink so much and my worst fear is that I can't use it up before I die. This is why so-called "philantrophists" exist. Old men with no offspring but excess money who can't find a purpose for it. Sad. Just today I gave a few bucks of the soon to be worthless "Green Toilet Paper" or, short, GTP, to a family living in a bus.

I learned their story in return (before the got the GTP). Got a priceless lesson  on how to survive greedy landlords. By living in an ex-public transport bus they bought for $5000. God bless the USA ! The land of opportunity where milk and honey flows ! Not.

 

Watch the movie "Elysium". This is what the "Owners Of The World (and the owners of the political critters) have planned for you. Yeah, it's a fictional movie and the space station is nonsense (because of the radiation alone) but the conditions on Earth as depicted in the movie are very very plausible.  (Sorry for being off topic here, but pointing at it may save a few families of my readers).

 

- Uncle Bernie

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Hi Bernie,Please don't

Hi Bernie,

Please don't interpret the extra care I am taking as an insult, or that I have any doubts about the quality of your parts kit. If anything, you should take it as an indication of the amount of respect I have for the all the effort you have put in to make these kits available. Bear in mind my perspective. To me the 2519 is made of pure unobtainium, and I wanted to be as careful as possible to make sure I didn't let the 'magic smoke' get out from inside of it. You'll note that once I got to the point where I was confident enough to put in the 2519, I did go 'all in' at the table as you say. Although I did reserve myself some 'taxi fare' to get home from the casino by leaving out the second row of DRAM. I have read somewhere around here that the second row of RAM is something that pushes the Apple-1 design that much closer to the cliff of no return.

By the way, those of you who are paying attention may have noticed that by using Bernie's kit, I made it all the way from an empty board and a bag of parts to the backslash-@-sign prompt with ZERO PROBLEMS WHATSOEVER. What more of a testimonial can there be?

 

Thanks and with Best Regards,

Jeff M.

 

 

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About partially populated boards (again) and replacement ICs

In post #23 jmmh wrote:

 

"To me the 2519 is made of pure unobtainium."

 

Uncle Bernie comments:

 

For the buyers of my kits, its not "unobtainium" and since you bought such a kit, I can replace any IC in it you might blow up. You just have to send the bad IC back to me (yes ! So it compare it to the photos I have from every kit) and I will check myself if it's really bad or limping (I also want to learn and document all possible symptoms). The replacement and return postage has to be paid by the builder only if the IC was blown up by mishandling it (yes I can tell why it died). If it was infant mortality or some form of limping producing effects I could not have seen in my burn-in rigs, the replacement is free. Guess how many ICs I had to replace in all these years on my own dime ? Two. These were PROMs which had a growback issue with a fuse. These things can happen. This is why fuse link programmed PROMs and PALs quickly disappeared when EEPROM based drop-in substitutes came out. Of course I did have a few cases where dishonest people wanted to push their IC junk on me which they had bought elsewhere. Does not work as I have close up photos of each and every IC I ever sold in these kits. Ask any customer service rep at any big box store and they will tell you stories ...

 

WHY PARTIALLY POPULATED POWER UPS ARE DISCOURAGED

 

Now here is the reason why I don't like the partially populated power-ups: depending on which ICs are missing, the behaviour of the partially populated Apple-1 can be unpredictable. And then some builders get spooked and start swapping ICs ! And make matters worse ! Mike Willigal's otherwise great building instructions are the worst offenders here, as they suggest to test the terminal section first and leave the processor section unpopulated. This alone has cost me dozens of emails to calm down frustrated builders. So I added the "fully populated" rule to my Tips & Tricks pdf. Because after all supply voltages have been checked to be good on the first - sockets all empty - powerup, it is impossible to destroy any IC unless it is put in backwards or zapped by ESD. So nothing can be gained by partially populated power-ups.

 

BEWARE THE EMPTY KEYBOARD SOCKET

 

The next massive problem I ran into with these kits was the empty keyboard socket. This was before the "gimmick switch" and before the diagnostic page in the PROMs. Upon power up, the Apple-1 would enter the Wozmon (after reset with a wire - yikes ! Don't do that !) and due to the lacking keyboard, the PIA would pick up erratic strobes out of the nowhere and random characters would appear as if entered by a ghost on a ghost keyboard. Which spooked the builders ! To make matters worse, some did not clear the screen before the reset, leading to even more trouble.

 

Introduction of the "gimmick switch" solved the CLR SCREEN problem and the introduction of the diagnostic page in the PROMs did away with the erratic phantom keyboard entries (as it does not look at the keyboard port at all). The psychology behing this is trivial - running the diagnostics builds confidence that the build is good, and then when running the Wozmon with no keyboard, and random characters appear, panic reactions are rarer and less severe.

 

THE POWER ON SCREEN PATTERN MYTH

 

Finally, I'm still struggle with getting the false information / myth out of the heads of the builders that the Apple-1 must have the @_@_@_ ... screen pattern after power up. Some people have brought this myth in circulation and now some builders get spooked whenever a few characters appear after power up which are not @_@_@_ ...  this is normal and expected, folks. Only get worried when after a CLR SCREEN some unexpected crap appears on the screen. Everything else is irrelevant as the screen contents after power up depends on so many unfathomable factors that it's meaningless. Only true Apple-1 experts can "see" certain ills in the power up screen and use it to diagnose which ICs may be bad. Everybody else please ignore it and give it a CLR SCREEN.

 

So far my comments. Of course anyone can bring up his/her Apple-1 build as desired, but don't take any phenomena seen with partially populated boards as the "gold standard" that needs to be expected for each and every build. We need to consider that in the meanwhile a lot of beginners venture into building an Apple-1 (hey, why don't you beginners go build a simpler kit first ? Such as electronic dice ? And after that, a Briel Replica-1 based on modern ICs - muuuch less money at stake than with a real Apple-1 kit ?) and these beginners better don't see instructions for experiments with uncertain outcomes.

 

Other than that, I of course appreciate this thread which shows how a new Apple-1 clone is being made and "born".

Let us know the rest of the story, too !

 

- Uncle Bernie

 

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Nice one. I would recommend

Nice one.

 

I would recommend basic in EPROM as it makes the machine almost useable ;)

 

I just need to finish off testing my EPROM board (but a couple of CBM PET 8032-SK's are also taking up my time at the moment).

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