A few years ago I designed some Apple 1 peripheral boards which I have documented on my web site Apple1notes.com. I have some extra bare boards and I am considering selling some sets of those boards. The boards include:
Expansion board with three sockets and 1 edge connector for daisy-chaining. The Expansion board buffers most of the signals with the Data lines optionally buffered and jumpers to manage the data read/write when buffered. I have tested up to three Expansion boards daisy chained.
The FRAM board can provide memory expansion and replacement for the onboard DRAM and ROM with non-volatile memory that retains it’s contents when powered down. To get the most out of the Board the Apple 1 VMA line which is jumpered to 5 volts should be reenabled by replacing the jumper with a shunt RC to allow the onboard DRAM and ROM to be disabled by the FRAM board on a cycle by cycle basis. The memory space is managed in 4K blocks with switches and jumpers so blocks can be configured as FRAM off, FRAM R/W, FRAM Read with DRAM Write, or FRAM Write with DRAM Read. The 0 block can be configured as FRAM R/W or DRAM R/W and the F block can be configured as FRAM Write with ROM Read, FRAM R/W, or FRAM Read Only. The board is also useful without the VMA Mod to provide non-volatile RAM in open address space.
The Serial Board is 6551 based and can replace the Apple 1 Keyboard and/or Apple 1 display routing input and output to the Serial path. This board also uses the VMA line to disable the onboard I/O as needed to take over the functions but can be used as a Serial Board peripheral without the Mod since the 6551 registers are available to software. The 6551 does need registers initialized to function properly.
The USB board is based on a custom device called Easy Input designed by Mark Lincer under the name Radovan. The parts are no longer available but I have a pretty good stock and will provide one with the boards, probably mounted on the board since that is the easiest way to ship it. The USB board captures the display output from the Apple 1 and creates an output that looks like it is coming from a USB keyboard. This allows you to put the the Apple 1 display on a Mac in a properly formatted Text Edit window using the proper font. With a USB to Bluetooth converter you can even get the Apple 1 display on your iPad or iPhone. This board also uses the VMA line for reliable operation but seems to work ok without it showing output on both the Apple 1 Video and Keyboard output.I have attached some documentation and
has more information and videos that showcase these boards. The three peripheral boards can be set up to either plug into the Expansion board or plug directly on to the Apple 1 or Clone on the peripheral connector with an optional board connector.
My plan would be to sell the three bare peripheral boards, bare expansion board and Easy Input device for around $50. I will not be as available as I would like to provide support as I am very busy as primary caregiver for my wife.
I would like to know if there is any interest.
I forgot to include this YouTube link that demos the FRAM board modifying the monitor code and saving it.
I'm definitely interested in two sets. Would be very useful for my two mimeos. Thanks for posting the pdf and vid link.
I'm interested in a set if any are still available.
I still have boards, I sent you a PM.
I leave the ACI on the Apple 1 unless I am using the CFFA1 card which is difficult to use on the expansion card because it directly maps some address space which doesn't work with the expansion board using buffering. If you mount the optional connector on my other cards for use directly on the Apple 1 expansion connector then the other cards cannot plug into the usual ACI connector (see Figure).
Hello Wendell,is it allowed to ask further technical questions about your great expansion solution in this thread?Or should it be more about expressions of interests here? what also o.k. would. Alternatively, would I possibly open a new thread for it? .
My question about expansion board.
=> I did the ACI test as described in the instructions. The ACI ROM also reports normally with 100.104I haven't done a VMA MOD yet.But if I want to save something on my ACI, the header is missing on the cassette.(the short start tone of approx. 4 seconds before the actual program is missing).Question: You have probably already saved something on a cassette via ACI, if only the ACI card is also in the expansion port?To be on the safe side, can you name the correct jumpers again?For the test, I had set the jumpers as described in the instructions on page 7 Figure7 ..(V = ON; R = ON, S = OFF, T = OFF, and VMA open)and on the Apple1 main board are soldered:(on the mainboard I have R + C (S + T not bridged), RAM address space: X to $ 0000 and W to $ E000, Z on D and Y on F.
Thank you very mutch... greetings Mikel.
I checked the problem you described, I had not used the ACI on the Expansion board for saving programs very much and what I learned was I have two ACI's that work correctly on the buffered expansion board and two that do not? All boards work for reading programs and work for writing if you use the expansion board unbuffered. It seems likely that the problem is a noise problem but one of the boards that works and one that doesn't both have added filter caps and one each do not?? I will spend some time trying to figure out the difference. If you use the Expansion board unbuffered the R,S and T settings should all be off. It is best to keep the ACI on the mother board socket.
This is probably a pretty good place for questions on the boards. I have very limited time but I will do what I can. I hope others wil become the experts. Usage will hopefully get all the bugs identified and worked out.
Thank you for the quick reply.I will then test as suggestedand check if the ACI works on the mainboard while expansion port is plugged but R,S,T = Off
(also V = Off) and VMA (not connected t, I haven't done VMA Mode yet either).
It's just strange that the header beep at the beginning of the save process doesn't work, otherwise data (signals, at least acoustically) is coming.
If the ACI card then works, I will test my FRAM card (without ACI) on the expansion port in the next step and then in combination with ACI.
Thank you and greetings from Europe
The FRAM card is set up and tested according to the instructions.(plugged into all 3 slots and tested the memory with the memorry6502 check.)It shows no errors and works even when the BUFFER is OFF.
on the Apple1 board I still have memory mapped at $e000 and 0000.
Unfortunately, the ACI card can still NOT save on the expansion port. The header TON comes out "alienated".
I think it's because of the "buffer" ?? and without a buffer, the card on the expansion card doesn't seem to work at all.
In the next step I will test the juke box card on the expansion card (without the FRAM card, of course).
The problem with trying to buffer an expansion board is how to manage the data buffer which has to be bidirectional. When the processor perforns a read operation the expansion buffer should only drive the data bus when the board with the address being read is on the expansion board after the data buffer. The way that can be determined in the Apple 1 is if the R, S, or T lines are being used to address the board on the expander or if the VMA line is being used by a board on the expander board so the data buffer on the expander will only be enabled when the R, S, T, or VMA line is being used and the expander is configured to recognize the signal(s).
If the expander board is configured for Unbuffered as shown in the Photograph and Schematic then any board can be used on the expander whether they use the R, S, T and/or V or not, as you can see from the schematic in unbuffered mode the Processor data bus is simply passed through. The advantage of buffering is that board load with multiple boards is less of a problem. The 6502 directly drives the data bus and is only specified to drive 1 TTL load.
Expansion UnBuff .jpg
I would like to add, that the schematics shown above do not have the error like the others you find elsewhere. On the others the connection from J11.1 to TL is drawn a bit to far left and looks like it's connected to all the resistors it passes by on the right side,
The Apple ACI card is a bit special as to my understanding this card is a readonly device. Even the writes to tape are triggered by read accesses to a mirror of the PROMs. Reads from tape are done by reading from a mirror position of the PROMs.
Hello Wendell,we are currently in the process of building your beautiful serial card.Unfortunately it does not work at the moment.Should it also work with a simple RS232 3-wire connection?
or in this case you have to bridge other signals to the Apple first RTS / CTS etc. ( the Modem is woriking at an other PC)Thanks for a feedback.. Have a good time!
The simple connection should work. There is a video that might help if you haven't seen it.
For 300 baud you need to set D004 and D005 to 8B 96.
I don't have any free time right now, sorry I can't help more,
Hello Wendell,We are happy if you still have time in between, otherwise enjoy your family and your free time.
Just a short question.Is the main function of the serial card is to use another "PC" as a terminal for the Apple1 as a matter of priority.
Our rebuild card works like this now (the quartz was defective at first).
Or you can use it to connect a "real" analog modem with 9600 baud and make calls to BBS.A small program will probably be needed for this.
Or is that generally not possible.The 2 stop bits are not that easy for this.Many ThanksMikel
The functions in the instructions (connected to a PC with Hyperterminal) work correctly so far.The question is whether there is a terminal program to operate a modem with it.
I don't have an Apple 1, but it shouldn't take much to write a very simple terminal program to operate a modem. It would probaly need to be written in 6502 assembler. It would be more work to implement features like serial port configuration, auto-dial or any kind of logging or file transfers of course. But just reading and writting characters from the 6551 and displaying them on the screen and taking input from the keyboard shouldn't be that hard. I've written code like that for the Apple II and other machines, although many years ago as there isn't much demand for async communication anymore.
Wait... if you can communicate to a PC, it is just configuration to talk to a modem... And the right cable of course. You should be able to type the Hayes style "AT" commands to dial and stuff.
The Serial Board can be used in two fundamentally different ways. The simplest way is to simply plug in the board and write your own 6551 serial code application using addresses $D002 through $D005 to access the 6551 Registers. If the VMA line is not disabled on the Apple 1 then the number J8 should be removed and the two toggle switches should be off.
The other mode of operation uses the VMA line on the Apple 1 (which needs to be activated) to disable the Apple 1 6820 and substitute the Serial Input and Output for the Apple 1 Keyboard and Display. In this case the VMA line on the Apple 1 must be reactivated, the 6551 initialized after power on since there is no program to initialize it, and the toggle switches turned on. In this mode the Keyboard is replaced by the Serial Input and the Display is replaced by the Serial Output by disabling the 6820 and emulating the 6820 on the Serial Board so that the Apple 1 operates normally while the input and output are replaced.
It was observed that the ACI did not function properly on write operations when installed on the Extender Board. I found that some ACI’s worked and some didn’t. The first photo shows signals on a failing ACI, The Ph2 line on the ACI board is ringing causing the Data FF to get double clocked on the noise.
On the Extender board the Ph2 line goes through a 100 Ω resistor to a buffer before reaching the ACI. Adding a 47 pF capacitor to the Ph2 line after the 100 Ω on the Extender fixes the problem. The next photo shows the Ph2 and FF Clock after the addition. Also shown is an updated schematic showing the fix and how the 47 pF was added to the board pretty easily.
Expansion Rev 7Sch.jpg
Thank you for your reference to the serial card ...
and also the tip about the ACI on the expansion port.
I currently have a little problem with my Apple Repro. In fact, it works flawlessly.I also used Wendell's expansion card.
For this one should make the VMA MOD, for this the jumper on the 6502 at position A8, the jumper is opened and replaced by a resistor with 2200 Ohm and 100pF.The cards from Wendell (RAM expansion, serial card) also work with it.
But now I had to temporarily remove the VMA MOD for another expansion.Now I can't reset the computer after switching it on ?!The CPU does not bring a cursor.
However, if I leave the jumper open, the Apple1 works again. What is the PIN5 on the 6502 CPU for?What could have happened because before I could still connect the jumper on A8, not anymore?i measure 2,1Volt from PIN5 6502 to ground... and then the A1 works normal.With 5V (pin8 to pin5 will connected) i cant reset the System ??! (reset yes, but no cursor)
strange phenomenon.Thank you MIkel
now,.. my VMA Mod and also an 5V-Jumper at 6502 8A works...
the reason was an damaged IC "DM74H00" at Position D10 :)
now my apple1 works also fine angain... thank you
Where can I download Gerber files？
my last "expansions-Card"..the WOZ Adress Display