Problem with "ROM BOARD V 1.2" - EEPROM programmed correctly?

[Raaalf]

Hello PAL-1 User,

I have a problem with the ROM BOARD V1.2 or the included EEPROM Winbond W27E257-12.

The EEPROM that came with the ROM BOARD V1.2 was empty (I think).
I programmed the "PAL1_ROM_v1.0.bin" with my MiniPro TL866A.

Unfortunately, the PAL1_ROM v1.0 software cannot run. The menu is not displayed.

"KIM
8600 EA A 000<space>
A000 4C G
PAL-1 ROM Loader v1.0
(B)ASIC, (F)ORTH, eWo(z) Monitor, or e(X)it?"

Are the settings I used to program the EEPROM correct?

The jumpers on the ROM BOARD V1.2 are set correctly.

I need help please.

Greetings

Ralf

[Ronny Ribeiro]

Ralf, I think you need the 32k memory board working in tandem with the ROM board.
The code in the ROM uses memory mapped to the RAM board address.

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[Raaalf]

Hello Ronny,

I have the 32 KByte memory board and the motherboard.

Unfortunately, the menu is not displayed even with the memory board.

I would first like to rule out errors when programming the EEPROM.

[Ronny Ribeiro]

I see.
The programmer settings seems ok.
Have you tried to use KIM monitor to check the contents of the programmed ROM?

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[Raaalf]

Hi Ronny,

first: Thank you for your posts!

I'm a complete beginner. I have to read up on how I can read the content of the EEPROM in the KIM monitor.

Greetings

Ralf

[Ronny Ribeiro]

No problem!
You should read about the KIM monitor, indeed.
I assumed you have connected your PAL to another computer via serial, is that correct?
In PAL's documentation there is a small program for you to type in the keypad tô get familiarized with KIM monitor. Have you tried that?
Checkout pal.aibs.ws/support
The documentation to get started is there.

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[Raaalf]

Hello Ronny,

the serial connection to a PC works.

I think my PAL-1 has a problem with the expansion port.

I entered the program from the PAL-1 manual, page 32, using the PAL-1 keyboard:

The 32 Kbyte RAM board was not connected. The program worked.

Then I connected the 32 Kbyte RAM board directly to the PAL-1 and removed the jumper JP2.

After entering the program (start address changed from $0000 to $2000), the LED display goes dark after starting the program. Nothing happens. (The address range $2000-$FFFF is occupied by the 32 KByte RAM board.)

[Raaalf]

Hi Ronny,

I took the UM6532 from the "PAL-1 2nd RIOT Expansion Kit" and put it into the PAL-1.

With the 32 KByte RAM BOARD connected, I ran “Bob’s Memory Test”. Without errors.

Then I loaded "Microsoft Basic V1.1" and was able to start it. This didn't work with the original UM6532 of the PAL-1.

My suspicion of the defect was confirmed. Now I just need a "new" UM6532 from Liu as a replacement.

I´am sooo happy! ;-)

[Raaalf]

Loading "Microsoft Basic V1.1" in papertape format with Tera Term takes about 9 minutes. My Tera Term settings are: Transmit delay 20 ms per character, 200 ms per line and, when sending a file,
10 ms per line.

Are the delays too conservative? What are the minimum delays that work in practice?

P.S. Unfortunately, the "ROM BOARD V 1.2" doesn't work yet.

[Raaalf]

OK.

The problem with the "ROM BOARD V 1.2" is circled.

The problem is the "PAL-1 Motherboard Expansion Kit". The first two slots of the "PAL-1 Motherboard Expansion Kit" works.

I first inserted the "ROM BOARD V 1.2" into the last slot. Now the "32 Kbyte RAM board" is in the first slot and the "ROM BOARD V 1.2" in the second slot. This works

[Ronny Ribeiro]

That's good news!
Now check the motherboard for bad solder joints, damaged tracks, etc.
My motherboard accepts cards in any position so should yours.
Debugging is the great adventure, isn't it?!

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[Jim McClanahan]

I have found that board order does matter. I can't explain it (because it will vary a lot), but have experienced it. You also see that on some of the other simple passive bus systems (like the RC2014). There is a lot of stray capacitance and inductance in the ribbon cable and expansion card holder.

My recommendation would tend to be to get things physically solid (by mounting the motherboard and the expansion bus on a base--I use a chunk of particle board shelving material that I painted black). What works with the expansion card in one position might not work if you move things around. Once that variable is out of the way, then find the card order that works for you.

I had forgotten that I had that problem and will revise the ROM documentation on my github page to have a troubleshooting section.

I have a new plexiglass base I was going to use, but will probably use for the PAL-2 now. They are fairly cheap pre-cut to common sizes out on the auction site.

I'm attaching a picture of the first breadboarded EPROM board that I used to develop and test the ROM images. It was very temperamental and I was careful not to move stuff around on the workbench. :-)

Thanks,

Jim W4JBM

"With a soldering iron in one hand, a schematic in the other, and puzzled look on his face..."

https://github.com/w4jbm

[Ronny Ribeiro]

Thanks for the clarifications, Jim!

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[Raaalf]

Hi Jim,

thank you for the explanations about the motherboard, the bus system and what needs to be taken into account for problem-free functionality.

For the PAL-1 I ordered wooden multiplex boards cut to size. The PAL-1 is permanently mounted on this. A wooden desk case fits the character of a KIM-1 clone very well!?

[Raaalf]

Hi Ronny,

oh yes! Troubleshooting is a great adventure! With current PCs, troubleshooting is no longer possible as close to the hardware as with the PAL-1. ;-)

I re-soldered all the soldering points on the motherboard. Now the expansion boards work in all slots. Still, I only use the front slots.

It's great that there is so much software, manuals, information, great websites (Hans Otten's website for example) etc. about the KIM-1.

On the other hand, you have to study the KIM-1 intensively and read all the information.

[Ronny Ribeiro]

Em sáb., 1 de fev. de 2025 10:08, Raaalf <raaaaaaaaaaa...@gmail.com> escreveu:

Hi Ronny,

oh yes! Troubleshooting is a great adventure! With current PCs, troubleshooting is no longer possible as close to the hardware as with the PAL-1. ;-)

You definitely right! You can get to know every bit of hardware and software on your PAL, Wich is almost impossible with modern computers.

I re-soldered all the soldering points on the motherboard. Now the expansion boards work in all slots. Still, I only use the front slots.

Good to hear that! As I told you, I haven't had any problems with slot order on my motherboard, perhaps because it's solidly installed.

It's great that there is so much software, manuals, information, great websites (Hans Otten's website for example) etc. about the KIM-1.

Yes! A very though processor with a long lived story that left a trail of literature behind, that's what the 6502 is!

On the other hand, you have to study the KIM-1 intensively and read all the information.

Yes, mandatory 😂 Checkout Ben Eater's series about his 6502 breadboard computer on YouTube if you haven't yet. It's very interesting!

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[GN Liu]

Hi Raaalf,

Has your issue been resolved?

Liu

[Raaalf]

Hi Liu,

the problem could be solved. I took the UM6532 from the "PAL-1 2nd RIOT Expansion Kit" and put it into the PAL-1.

With the 32 KByte RAM BOARD connected, I ran “Bob’s Memory Test”. Without errors.
Then I loaded "Microsoft Basic V1.1" and was able to start it. This didn't work with the original UM6532 of the PAL-1.
My suspicion of the defect was confirmed.

I need a "new" UM6532 from you as a replacement.  Thank you!

Ralf

[GN Liu]

Hi Ralf,

Sorry about the issue, old chips occasionally fail unexpectedly.
I can send you a replacement 6532, please check your email for my reply.

Liu