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General Category => Technical support - Hardware related => Topic started by: Audronic on 01:22, 13 July 19

Title: Amstrad CPC464 40009 Rom Replacement
Post by: Audronic on 01:22, 13 July 19
Hi All


Amstrad CPC464 40009 Rom Replacement (13 July 2019)

The file Name is :- 40009-R2.rom (Ready to Burn to 27C256 ROM)

The file replaces the 40009 rom in a CPC464.

It is based upon the rom in a CPC6128 (40025)

It gives you 32 Roms for MegaFlash
Opening screen Shows AWA 64K Microcomputer (v3) etc:-

Basic 1.1

Thanks to RedBox for the 32 Rom Patches
I had to alter the checksum for it to work in the CPC464

Ray
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: wed on 17:46, 23 September 22
Thanks very much for posting.

I had a broken 464 which, among other faults, turned out to have a faulty 40009 ROM.

Fortunately, I had a spare 27c256 EPROM, salvaged 10 years ago from an industrial machine. Cleared it with a COVID UV sanitizer light, wrote a program on an AVR microcontroller to write this ROM, and on installing it into the 464 last night, it came back to life!

Looking forward to getting some cassettes tested out and checking the rest of the computer is working fully.

Many thanks again for helping me to fix my computer!
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: SerErris on 00:47, 10 November 22
Sounds great, so it gives you CPC 464 with Basic 1.1 ? 

What about the jump tables to firmware? Does it change anything there (e.g. now 664 tables instead of 464 tables?).

Is it possible to still let it show Schneider instead of Awa ? 
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: WacKEDmaN on 04:37, 10 November 22
it has 6128 firmware so 6128 tables.. gives extra keywords in basic..like FRAME, FILL, WINDOW etc...and the some of the call addresses are moved... its basically just 6128 ROM patched show 64k instead of 128k (aswell as the 32x rom patches)

the manufacturer name should be setable via the LK#s connected to the PPI

because there is still no AMSDOS, it defaults to tape outta the box...
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: eto on 08:16, 10 November 22
btw: is there any benefit of using the 6128 ROM instead of the 664 ROM? I have put the 664 ROM into my 464 as this felt like a "more natural" fit. 
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: TotO on 08:30, 10 November 22
The CPC ROM is a 32K circuit with lower 16K (firmware) and upper 16K (BASIC) split by switching address line A14. There is no jump table problem, except on emulators because they wrongly split the CPC ROM into two 16K files (MAME use a 32K file).

For information, to fix CPCs, I probably have some spare original ROMs left.
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: SerErris on 21:55, 10 November 22
@TotO 

I am talking about the jump table vectors that differs between the firmware of 464, 664 and 6128. And obviously basic is also different between 464 and 664. So If it is a 6128 ROM with just 64k then I do understand what it is and that was actually my question. :-)
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: vargham on 17:41, 01 March 23
I tried this ROM in my Schneider 464 and it crashes. I also tried unmodified 664 ROM with the same result.
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: eto on 18:28, 01 March 23
Quote from: vargham on 17:41, 01 March 23I tried this ROM in my Schneider 464 and it crashes. I also tried unmodified 664 ROM with the same result.

I tried it with both 664 and 6128 ROMS and I had no issues. 

Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: vargham on 18:36, 01 March 23
My computer starts up normally.
10 MODE 2
20 PRINT "Test ";
30 GOTO 10
This program prints a few lines then crashes.
Syntax error in 10
10 PRINT "Test ";
If I connect DDI before running this program, the computer prints a whole page, then crashes. The message is press play on tape.
Title: Re: Amstrad CPC464 40009 Rom Replacement
Post by: vargham on 20:03, 02 March 23
I have tried with 3 different W27C512 EEPROMs. No good.
Changed to SST27SF512 flash, and working.
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