Hi,
I recently purchased a ZX Spectrum 48K Plus, issue3 mb but for some reason it thinks its a 16K machine,
If I run
PRINT PEEK 23732 + PEEK 23733 * 256
I get the answer
32767
I've replaced all the upper 32K Memory modules and it has made no difference
I've checked the links at the top of the board and they look correct
Anyone any ideas where to look next?
Thanks
Gareth
ZX Spectrum 48K Issue 3 thinks its a 16K
Re: ZX Spectrum 48K Issue 3 thinks its a 16K
For Issue 3 boards it is essential that all extension RAM ICs must be of the same type.
Possible that one of this ICs is broken: IC 23 (74LS32), IC 24 (74LS00) or IC 25, IC 26 (74LS157 NOT National Semiconductor)
Also possible is a broken PCB connection...
Possible that one of this ICs is broken: IC 23 (74LS32), IC 24 (74LS00) or IC 25, IC 26 (74LS157 NOT National Semiconductor)
Also possible is a broken PCB connection...