Finally I’m building the ST536.
I was wondering if somebody can help me in getting a programmed rom ic with the patched TOS.
As I’m in The Netherlands I can’t buy in the Exxos store and I don’t have the correct programmer..
Can all registered uses please login, even just for a few minutes..
It helps build a picture where our "good traffic" is coming from..
Thanks :)
It helps build a picture where our "good traffic" is coming from..
Thanks :)
ST536 ROM chip help
Re: ST536 ROM chip help
Ok I’m really slow.
ST536 seems completely soldered.
I hope this will work.
now
ST536 seems completely soldered.
I hope this will work.
now
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Last edited by exxos on Sat Sep 26, 2026 1:19 am, edited 1 time in total.
Reason: Spacing around attachments corrected
Reason: Spacing around attachments corrected
Re: ST536 ROM chip help
What revision board is it ?
Re: ST536 ROM chip help
It says revision 5..
Does it need any bodge fixes / mods before I try?
Or just flash it and go.
Does it need any bodge fixes / mods before I try?
Or just flash it and go.
Re: ST536 ROM chip help
So tried the board. It sometimes works but mostly doesn’t not sure why.
Tried most firmware versions and two cpu’s and two mb.
Does it need additional something to get it stable? I see one cap is missing at the bottom..
Tried most firmware versions and two cpu’s and two mb.
Does it need additional something to get it stable? I see one cap is missing at the bottom..
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- IMG_1850.jpeg (132.37 KiB) Viewed 39 times
Re: ST536 ROM chip help
I don't think you have said what machine you are fitting it on ?
I'm not entirely sure which board you are actually building as the original rev 5.00 used the 144XL PLD. Are you using the 144 or 288 ? The 288 needs a 6ns PLD and can use the later firmware. Its a 5 years old card now and needs a lot of mods which are documented on the install page... They haven't been tested on a the 144XL either. So we need to know what PLD you fitted there and what firmware you are trying to flash.
It's also unclear what you mean by on stable and sometimes working and sometimes not ? If it is not booting on power of then likely your reset circuit is bad. You also need to make sure you're using the latest 206 ROM as well. and remove the ROM from the motherboard. Also make sure you're using a re-capped Power supply at the minimum.. You also need a heatsink on the CPU..
I'm not entirely sure which board you are actually building as the original rev 5.00 used the 144XL PLD. Are you using the 144 or 288 ? The 288 needs a 6ns PLD and can use the later firmware. Its a 5 years old card now and needs a lot of mods which are documented on the install page... They haven't been tested on a the 144XL either. So we need to know what PLD you fitted there and what firmware you are trying to flash.
It's also unclear what you mean by on stable and sometimes working and sometimes not ? If it is not booting on power of then likely your reset circuit is bad. You also need to make sure you're using the latest 206 ROM as well. and remove the ROM from the motherboard. Also make sure you're using a re-capped Power supply at the minimum.. You also need a heatsink on the CPU..
Re: ST536 ROM chip help
Its a rev 5 board.
Machine tested: H5 and 520 ST (short board with 4 mb).
Rom is flashed with what I could find on the last upgrade page.
First half of rom does not seem to work at all (I assume it should be emutos).Second half is 2.06.
When I install it sometimes shows the atari logo and if it does that the mem test will work. It sometimes boots from acsi but mostly just crashes after the mem test bit. When it boots from acsi I can sometimes run some stuff but it mostly freezes. Very often it just shows a white screen.
Also tested the 1.04-2.06 rom from the mb of the h5. Same behaviour from the tos 2.06.
But I could retry burning the rom… Was just wondering if something special needs to be done.
It does not like to have anything on the ide as well. Then for sure white screen. It uses an 144xl. I bought this stuff years ago. So its a bit old… but never build till now.
Mb rom is ofcourse removed. Heatsink on the cpu… That can’t be the issue had these things in the Amiga 500 without any heatsink for years. The issue is directly at boot..
Machine tested: H5 and 520 ST (short board with 4 mb).
Rom is flashed with what I could find on the last upgrade page.
First half of rom does not seem to work at all (I assume it should be emutos).Second half is 2.06.
When I install it sometimes shows the atari logo and if it does that the mem test will work. It sometimes boots from acsi but mostly just crashes after the mem test bit. When it boots from acsi I can sometimes run some stuff but it mostly freezes. Very often it just shows a white screen.
Also tested the 1.04-2.06 rom from the mb of the h5. Same behaviour from the tos 2.06.
But I could retry burning the rom… Was just wondering if something special needs to be done.
It does not like to have anything on the ide as well. Then for sure white screen. It uses an 144xl. I bought this stuff years ago. So its a bit old… but never build till now.
Mb rom is ofcourse removed. Heatsink on the cpu… That can’t be the issue had these things in the Amiga 500 without any heatsink for years. The issue is directly at boot..
Re: ST536 ROM chip help
This is the latest ROM, I don't believe it is on the website yet.. It fixes some minor bugs over the last release on the site.
You want the section "MODIFICATIONS - All 2025 versions <5.60"
https://www.exxosforum.co.uk/atari/last/ST536/index.htm
But nobody has tried the current mods with the 144XL PLD that I know of, everything assumes a 288XL -6 now. So you should probably do the mods one at a time.. Start with the CPU resistor and STERM resistor fix.. White power wire fix. Also make sure you don't miss things like "BGACK needs a 1K pullup from (68K DIP) pin 12 (BGACK) to pin 14 (VCC 5V)."
I also assume you are using a 55ns ROM as various older versions need a faster ROM.. I also assume you purchased the CPU from the store, as there are a lot of bad 030 CPU's about to start with.
You also say you are booting from ACSI.. You need to make sure you are using the latest HDdriver and make sure you boot with no auto folder programs or accessories etc as they may not be compatible with a 030.. I really suggest booting from a plain floppy with GB6 on it at this point.
You want the section "MODIFICATIONS - All 2025 versions <5.60"
https://www.exxosforum.co.uk/atari/last/ST536/index.htm
But nobody has tried the current mods with the 144XL PLD that I know of, everything assumes a 288XL -6 now. So you should probably do the mods one at a time.. Start with the CPU resistor and STERM resistor fix.. White power wire fix. Also make sure you don't miss things like "BGACK needs a 1K pullup from (68K DIP) pin 12 (BGACK) to pin 14 (VCC 5V)."
I also assume you are using a 55ns ROM as various older versions need a faster ROM.. I also assume you purchased the CPU from the store, as there are a lot of bad 030 CPU's about to start with.
You also say you are booting from ACSI.. You need to make sure you are using the latest HDdriver and make sure you boot with no auto folder programs or accessories etc as they may not be compatible with a 030.. I really suggest booting from a plain floppy with GB6 on it at this point.
Re: ST536 ROM chip help
Thanks. Made a mistake programming the rom. So will first check if this causes the issue.