Hi all,
My CRTC 4 does not boot anymore, i have a blue screen, border is black and relay switch ON at boot.
Any idea about what is going wrong ?
A ram chip went bad maybe ? (As it tends to do that kind of symptoms... Is one of the chip hot ?).
No extension plugged in ?
Nothing's hot, no extensions connected.........
YUP, your RAM has probably died. They don't always get hot when they have failed.
Bryce.
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225): How to test the RAM chips with an oscillo ?
You can check the DataIN/DataOUT Pins on each chip to see if one of them is stuck, but the fastest way is to use @gerald (http://www.cpcwiki.eu/forum/index.php?action=profile;u=250) RAMTest ROM (assuming you have a device to install it on).
Bryce.
I will test RAM chips as I can not launch any soft or ROM....
The ROM gets installed as a lowerROM and doesn't need the RAM to work or the system to be bootable.
Bryce.
With an extension (m4), it does not boot ....does it means that i have another problem than RAM issue ?
That depends on what it's trying to boot. If it's trying to boot to BASIC, then that will still need RAM, so it's not going to boot. If you have installed geralds RAMTest (which doesn't require RAM to run) and it still doesn't boot, then you could have a different issue.
What were you trying to boot?
Bryce.
This ROM is for Plus ?
How to modify it to use on CPC old ?
This is the ROM you need installed in place of the LowerROM: http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/quick-and-dirty-ram-test-for-cpc/msg106676/#msg106676
Bryce.
Quote from: Kris on 12:46, 04 October 18
This ROM is for Plus ?
How to modify it to use on CPC old ?
It's working on any CPC, plus or not.
You just need a extension that can replace the lower ROM M4/XMEM.
You can even piggy pack a 32K EPROM on the SYSTEM ROM. You just need to force ROMDIS high on the CPC to disable the system ROM, and force the EPROM OEn (pin 22) low (and not connected to the original ROM)
Or connect that EPROM on the extension board. Same here, force ROMDIS high, OEn low on the EPROM and use ROMEN as CS for the EPROM
I can also have a look at it if you want.
I've been trying to install the ROM on my X mem (on Plus) but it does not work...
Quote from: Kris on 14:34, 05 October 18
I've been trying to install the ROM on my X mem (on Plus) but it does not work...
What is not working ?
Intalling memtest on the XMEM or memtest itself ?
Installing the ROM
The bin file has no header, I do not know if this can be a issue for the XMEM flash utility, as I don not use it (I use my programmer for this)
If you have a programmer, you can flash it at offset 7*0x4000 (ie ROM7).. after doing a backup of the original content ;)