Enterprise Forever
:UK => Hardware => Maintenance => Topic started by: gflorez on 2017.August.23. 18:52:40
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This is the fourth EP that I modify with a 64KB EXOS Eprom, and I have taken A15 from B9 at the External connector like before.
It is a German Keyboard unit, so I have also put a language Rom(ESB.Rom) on the cartridge.
It starts correctly, with the fast memory check from Zozo, then the flashing letters and enters Basic after a keypress.
Basic seems to work normally, but the :help command is answered with *** Not understood( *** No se entiende). Also, :wp gives the same results.
I have checked the Eprom, the Rom file, the A15 lead and the B9 solder point before writing here.
Any clue?
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:shock:
If you put same ROM files to the emulator it is will working? The ROM files which are included in the latest ep128emu ROM pack are working for me.
If the EXOS EPROM are working normaly then I think the problem with the cartridge (connector/pcb/eprom). For example one address line have wrong connection, then some ROM area will changed.
Another possibility: Too slow EPROMs also can do some mystic problems. The EXOS 2.4 set no memory waits at default then possible some too slow EPROMs will work with 2.1 and not with 2.4
At the relabeled chinese EPROMs you don't know the original speed rate :-( Unfortunately many European seller also sell a chinese fake chips :-(
If your programer can read the manufacturer ID and it is not match with the labeled name then easy to know it is a fake chip... also good idea see the chip size under the windows. The modern (not older than 25 years :-) ) EPROMs have a very little chips. If the chip near to same size with the window then it is old one from early 80's, which are relabeled, and possible it is a slow one.
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Yes, the same configuration on the emulator works good.
If I return the original chip to the socket it works good.
It behaves the same with or without the cartridge.
The Eprom chip is a modern one, extracted by myself from a Bosch injection module(Benz...). But just for reassuring I have tried with other totally different chip, also the UK version, with the same results.
I have also tried to pass the A15 lead by another zone, but again the same.
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What happen if you start in 64K mode?
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OK, I will try it and also a complete Ram check, thanks.
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It makes the same. It only behaves normal if another Basic Rom is found on the cartridge. The Ram tests where passed.
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I have removed the Basic Rom from Exos24es, the EP starts on WP but behaves the same when I type F8 and :help+Enter. *** Unrecognised command.
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I wrongly assumed that a German Keyboard EP has the same Exos.rom than an English keyboard one...
The cause was that EXOS24ES.Rom loads an English matrix keyboard at start.
I have to create a new Spanish Exos Rom for German keyboards.