Beginners guide to the Apple 1 Test program

6 posts / 0 new
Last post
retro_bill's picture
Offline
Last seen: 20 hours 39 min ago
Joined: Aug 5 2020 - 11:56
Posts: 111
Beginners guide to the Apple 1 Test program

While I am waiting for Apple 1 PCB to show up so I can begin my build, I decided to read the manual. In the manual is a test program written in 6502 machine lanuage.

 

So I decided to disassemble that code and turn it into readable 6502 assembly language. So for those of you who are interested in what the test program does or is looking to learn 6502 assembly language, here something to get you started.

 

 

AA9 00               LDA #$0          Load A (Accumulator) register with 0

  AA                     TAX                   Transfer what is in the A register to the X Register.  The contents of the A register are unaffected

  20 EF FF         JSR $FFEF       This is the output character routine in the Apple 1 monitor. Let the monitor do the work for you

  E8                     INX                    Increment the X register

  8A                    TXA                    Transfer the contents of the X register and put it in A register

 4C 02 00         JMP $0002     Jump to the TAX instruction to get the Next Character and after we get to the last character the program starts over

 

All the instructions and numbers are in hexidecimal. 

 

I hope this will peak your interest and you will want to learn 6502 assembly language.

 

If you have any questons, please ask.

 

Bill

 

 

 

 

 

 

 

Offline
Last seen: 6 hours 1 min ago
Joined: Jun 29 2018 - 16:55
Posts: 123
This is good stuff, thank you

This is good stuff, thank you. I am closer by the year to acutally understanding this :P

 

I know you mentioned you are building a Replica1 as well. If you have not already, the downloads for the Replica 1 also have good docmentation and some programs available http://www.brielcomputers.com/files/r1pluscd.zip

 

The KRUSADER assembler documentation may also be of interest to you, as it is in ROM on the Replica 1. 

 

If you have questions along the way, particlarly with the Replica 1 or SD card from P-LAB, I'll have my eye on this forum and help if/when I can.

 

Cheers,

Alex

retro_bill's picture
Offline
Last seen: 20 hours 39 min ago
Joined: Aug 5 2020 - 11:56
Posts: 111
skate323k137 wrote:This is
skate323k137 wrote:

This is good stuff, thank you. I am closer by the year to acutally understanding this :P

 

I know you mentioned you are building a Replica1 as well. If you have not already, the downloads for the Replica 1 also have good docmentation and some programs available http://www.brielcomputers.com/files/r1pluscd.zip

 

The KRUSADER assembler documentation may also

Glad you liked it :)

 

Thanks for your help! After looking at the docs for the Apple 1 Micro SD card, you have to disable all the built-in full RAM expansion. So I decided to build a full Apple 1 replica, so I can take full advantage of P-labs SD storage card.

 

Cheers!

 

Bill

 

 

 

Offline
Last seen: 6 hours 1 min ago
Joined: Jun 29 2018 - 16:55
Posts: 123
There are no shortcomings of

There are no shortcomings of the P-LAB card on the Briel. Per Claudio, the jumper you are talking about:

 

"It disallocates RAM from 4000 to 7FFF from being handled by sdcard board, leaving it handled by Replica-1 builtin RAM."

 

The ram is still available to the user just handled differently. Claudio had me run some tests before also testing it himself I believe. Here is some info from our email exchange:

--

To be sure that everything is OK with RAM you could run the MEMORYTEST in UTILS folder.

It's the classic Willegal's RAM test:

 

  • Load it (don't RUN it)
  • RESET the computer
  • type 0:0 5 0 80 ENTER
  • type 280R ENTER
  • Wait for pass xx / fail (it will take a while)

 

This will test the entire RAM from 0500 to 7FFF.

--

 

Output on Briel Replica 1:

 

 

/UTILS>LOAD MEMORYTEST

FOUND MEMORYTEST#060280

LOADING

MEMORYTEST#060280

$0280-$03A1 (290 BYTES)

OK

/UTILS>\

0:0 5 0 80

0000: 00

280R

0280: A9PASS 01

Online
Last seen: 1 hour 32 min ago
Joined: May 4 2021 - 06:35
Posts: 79
You're both right...

Hi all,

regarding the microSD card you are both right.... :-)

Alex got the first version (1.13), which did not yet have RAM partitioning designed for Briel's Replica-1, in fact he had to make some "adjustments" by hand.

 

Bill will get version 1.18, that only needs the removal of the 3 jumpers to be compatible with the Replica-1:

- 1000-1FFF

- 2000-3FFF

- 4000-7FFF

 

It is all  in the latest version of the docs: 

https://p-l4b.github.io/sdcard/

 

@Bill: I've added a handwritten note to you in the package as a reminder, since you'll be using the card on both machines.

:-)

Cheers!

Claudio.

 

retro_bill's picture
Offline
Last seen: 20 hours 39 min ago
Joined: Aug 5 2020 - 11:56
Posts: 111
Gratzie Claudio! Bill

Gratzie Claudio!

 

Bill

Log in or register to post comments