Ruud's diagnostic ROM for IBM PC, XT and compatibles

modem7 · Aug 2, 2022

Ruud said:
What are the changes:
- If something goes wrong during the 2 KB test, offending address and the bad bits are shown.

For those with an IBM 5150, i.e. RAM chips in bank 0 are soldered in, showing the bad bit/s for the 'first 2 KB test' is a good improvement over the previous version. (Screen shot at [here].)

I have added a 'Ruuds diagnostic ROM for IBM 5150/5155/5160' link on minuszerodegrees.net (within the 'ROMs' section).
From that link, navigation is to four distinct web pages:
- ROM fitted to the 16KB-64KB version of IBM 5150 motherboard
- ROM fitted to the 64KB-256KB version of IBM 5150 motherboard
- ROM fitted to the 64-256KB version of IBM 5160 motherboard
- ROM fitted to the 256-640KB version of IBM 5160 motherboard

modem7 · Aug 3, 2022

alecv said:
Tested with XT-turbo clone, LPT card and 8 LEDs:

(DB-25, 8 LEDs and 8 resistors 240Ohm in serial).

It WORKS but it's rather uncomfortable to read binary code. Ordered this card:
https://www.ebay.com/itm/Laptop-MINI-PCI-LPT-4-digital-Tester-POST-CODE-Card/191674108413

To the 'Ruuds Diagnostic ROM' information that I have at [here], I have now added information ("Checkpoint codes" section) on the use of the 'parallel port monitoring POST board' that you ordered.

Ruud · Aug 3, 2022

Lex- said:
Hello @Ruud
thank you, ok, I will try the source code, can you share please your script that compile the source code and then copy the compiled file to the emulator?

nasm.exe diagrom.asm -f bin -l diagrom.lst -o diagrom.%Exten% -Z error.txt
nasm.exe diagrom.asm -f bin -l diagrom.lst -o diagrom.%Exten%
checksum diagrom.bin

The first line compiles the source and outputs the possible errors to a text file. The second line outpus the possible errors to the screen. The third line adjusts the checksum byte.
Sources and exe can be found in the attached ZIP file. Written using Free Pascal Compiler.

Lex- · Aug 3, 2022

Ruud said:
nasm.exe diagrom.asm -f bin -l diagrom.lst -o diagrom.%Exten% -Z error.txt
nasm.exe diagrom.asm -f bin -l diagrom.lst -o diagrom.%Exten%
checksum diagrom.bin

The first line compiles the source and outputs the possible errors to a text file. The second line outpus the possible errors to the screen. The third line adjusts the checksum byte.
Sources and exe can be found in the attached ZIP file. Written using Free Pascal Compiler.

Hi @Ruud
Thank you a lot.

ayandon · Feb 27, 2023

Dear @Ruud

I have two XT Clone PCs that I am in the process of restoring.
(One with Battery Damage. One recovered from a seller, never tested)

Spec: V20 Processor, Faraday FE2010A Chipset thing. It comes with a CGA card (and will build the Sergey's ISA Super VGA card soon.)

Copam B-190

Copam B-190 is a motherboard based on the Faraday FE2010A chipset. Get specs, BIOS, documentation and more!

theretroweb.com

Can I use your Diagnostic ROM with this system?

Ruud · Feb 28, 2023

Yes. But it won't work with the VGA card.

ayandon · Mar 1, 2023

Ruud said:
Yes. But it won't work with the VGA card.

Thats a CGA card....

Ruud · Mar 1, 2023

Then it should work. The remark about the VGA card was made because I got "complaints" that it didn't work with VGA cards. For the moment it won't. For an explanation, please see this so far unfinished page. (Sorry, due to a renovation I completely forgot about it)

ayandon · Mar 1, 2023

Ruud said:
Then it should work. The remark about the VGA card was made because I got "complaints" that it didn't work with VGA cards. For the moment it won't. For an explanation, please see this so far unfinished page. (Sorry, due to a renovation I completely forgot about it)

Ref: http://www.baltissen.org/newhtm/diagnosticROM.htm

If I can get VGA to work (I don't own EGA so I cannot test that), that will be version 3.

Eagerly waiting for the version 3

Atleast minimum support for Sergey's ISA Super VGA.

Ruud · Mar 2, 2023

I used to use Landmark but I had some thoughts about it and it seemed nice to create my own version. But until some on board memory had been tested, everything had to be done in ROM, thus including running subroutines using a trick: version 1. Then the idea rose to use a part of the video memory, the part outside the screen, as stack and that simplified a lot: version 2. If that works with CGA and MDA, why not with VGA? Which will be version 3.

The problem: due to a renovation I have a bad access to my hardware. The good news: the actual work has been finished, so it is now a matter of clearing everything and then find out where everything has been stuffed. Two very kind sons helped me to stow things away but forgot to note down where they put what. OK, that's life

FreddyV · Mar 2, 2023

A ROM like this is needed when there is a big problem.
In this case, there is a good chance that any video will work.
Then, ask for VGA support is the contrary of the ROM purpose....

Ruud · Mar 2, 2023

I know two men having a XT clone with a VGA card for the simple reason that they don't have a CGA or MDA monitor. They would be pleased with having a ROM that works with VGA. Just in case....

FreddyV · Mar 30, 2023

Ruud said:
I know two men having a XT clone with a VGA card for the simple reason that they don't have a CGA or MDA monitor. They would be pleased with having a ROM that works with VGA. Just in case....

Hi Rud,

Excellent job

Where can I find the last version ?
I would like to do an extended ROM version of your ROM, to play with it with my PicoMEM Board.

Ruud · Mar 30, 2023

Here is V2.

Makefile · Apr 1, 2023

Ruud said:
I know two men having a XT clone with a VGA card for the simple reason that they don't have a CGA or MDA monitor. They would be pleased with having a ROM that works with VGA. Just in case....

I actually started implementing polling mode serial output for that situation for the XT clone board I was fixing, but found and fixed the hardware issue before I got very far. It would require butchering TextToScreen, etc. to use ANSI escape sequences to move the cursor around among other changes.

Ruud · Apr 2, 2023

Hmm, it is an idea using a COM port for outputting data. I have thought about it before but having CGA and MDA at my disposal I discarded the idea. The advantage of this idea is that you can use any computer with a COM port to see what is going on. But I must assume that the user won't have a CGA or MDA card at hand which means I must use version 1 as base for this version.

Questions: I have programmed small programs to send data over the COM port but so far only between my own devices, for example between my C64 and a PC. If I use my laptop with PuTTY, do I need to use a protocol? Or will it just display the characters that I send? And how will it handle CR and LF?

With a bit of luck I'll be able to give my full attention to the VGA version again tomorrow.

ayandon · Apr 2, 2023

Ruud said:
Hmm, it is an idea using a COM port for outputting data. I have thought about it before but having CGA and MDA at my disposal I discarded the idea. The advantage of this idea is that you can use any computer with a COM port to see what is going on. But I must assume that the user won't have a CGA or MDA card at hand which means I must use version 1 as base for this version.

COM port Debugging will be a great help when lack of CGA/MDA card.
In that case, I do not need any VGA support

ayandon · Apr 2, 2023

Ruud said:
With a bit of luck I'll be able to give my full attention to the VGA version again tomorrow.

Eagerly waiting for this feature!

Makefile · Apr 2, 2023

Ruud said:
Questions: I have programmed small programs to send data over the COM port but so far only between my own devices, for example between my C64 and a PC. If I use my laptop with PuTTY, do I need to use a protocol? Or will it just display the characters that I send? And how will it handle CR and LF?

Will you need much more than to be able to reset (clear) the screen, position the cursor to some position, and output a string at that position (moving the cursor along the way)? ANSI escape sequences should be all you need. CR-LF will work as expected. I can't remember if you're using any IBM "extended ASCII" characters like line drawing characters, but you might want to take those out as well and replace with +, -, | so the user doesn't have to bother configuring their terminal program to use any character set but ASCII.

Here's assembly for a DOS COM program that does this--writing to the serial port but without using interrupts.


        cpu     8086
        bits    16
        org     100h

COM1            equ     3f8h
COM2            equ     2f8h
TXBUF           equ     0       ; Transmit buffer
RXBUF           equ     0       ; Receive buffer
DIVLO           equ     0       ; Baud divisor, low byte
DIVHI           equ     1       ; Baud divisor, high byte
INTEN           equ     1       ; Interrupt enable
INTID           equ     2       ; Interrupt identification
LINECON         equ     3       ; Line control
MODCON          equ     4       ; Modem control
LINESTAT        equ     5       ; Line status
MODSTAT         equ     6       ; Modem status

        section .text
start:
        cld

        ;; set 8-N-1 and flip to divisor access mode
        mov     dx,COM1+LINECON
        mov     al,83h
        out     dx,al

        ;; program 1200 bps
        mov     dl,(COM1+DIVLO) & 0xff
        mov     al,60h ; 0060h for 1200
        out     dx,al
        inc     dx      ; DIVHI
        xor     al,al
        out     dx,al

        ;; get out of divisor access mode
        mov     dl,(COM1+LINECON) & 0xff
        mov     al,03h
        out     dx,al

        ;; disable all interrupts from the port
        mov     dl,(COM1+INTEN) & 0xff
        xor     al,al
        out     dx,al

        ;; initialize modem control register
        ;; turn RTS and DTR on for max compat with terminal program on other end
        mov     dl,(COM1+MODCON) & 0xff
        mov     al,03h
        out     dx,al

        ;; send string
        mov     cx,HELLOLEN
        mov     di,COM1+TXBUF
        inc     dx      ; LINESTAT      
        mov     si,szHelloWorld
        .send:
        ;; implement timeout here...
        in      al,dx
        test    al,40h  ; transmitter hold register
        jz     .send    ; if it's busy, try again
        xchg    dx,di   ; TXBUF
        lodsb
        out     dx,al
        xchg    dx,di   ; LINESTAT
        loop    .send

        .done:
        mov     ax,4c00h
        int     21h

        section .data
szHelloWorld    db      27,'c'          ; ANSI escape to reset terminal
                db      27,'[12;34H'    ; cursor on line 12, column 34                        
                db      "Hello World!",13,10,"CR-LF works!"
HELLOLEN        equ     $-szHelloWorld

modem7 · Apr 2, 2023

ayandon said:
COM port Debugging will be a great help when lack of CGA/MDA card.
In that case, I do not need any VGA support

Right now, Ruud's diagnostic ROM presently outputs checkpoint ('debugging') codes to the parallel (LPT) ports of 378h, 278h, and 3BCh.
Those codes can be viewed via the modern device shown at [here].
More information about that is in the 'Checkpoint Codes' section in any of the five options at [here].

Ruud's diagnostic ROM for IBM PC, XT and compatibles

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