Hmm, loaded up Sanxion on another 48k+ I have here only to find that when it had loaded there were no enemies on screen, furthermore on loading Atic Atac the player sprite "slid" around and couldnt exit the screen
I would suggest running a diagnostic as the player sprite in Atic Atac sliding around suggests memory chunks being moved or corrupted in some strange way.
The usual suspects apply - ULA, processor, memory. My gut feeling tells me in that order. There isn't much else that can go wrong!
I'll guess that the most likely is a RAM fault, followed by a multiplexer (that interface the RAM to the Z80) fault, then maybe a Z80 CPU fault. I don't think a ULA fault would cause this, but may be wrong.
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Looks like it could be quite a localised failure in that IC as the memory between C000-FFFF checks out according to the test ROM, even though it's the same physical IC that provides 8000-BFFF.
This would explain why the symptoms are so specific (and benign for a RAM failure), and would seem to rule out a multiplexer failure also?
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Comments
My games for the Spectrum: Dingo, The Speccies, The Speccies 2, Vallation, SQIJ.
Twitter: Sokurah
I would suggest running a diagnostic as the player sprite in Atic Atac sliding around suggests memory chunks being moved or corrupted in some strange way.
The usual suspects apply - ULA, processor, memory. My gut feeling tells me in that order. There isn't much else that can go wrong!
Mark
Repair Guides. Spanish Hardware site.
WoS - can't download? Info here...
former Meulie Spectrum Archive but no longer available :-(
Spectranet: the TNFS directory thread
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
http://mdfs.net/Software/Z80/Exerciser/
B
zx-diagnostics - Fixing ZX Spectrums in the 21st Century (wiki)
Sinclair FAQ Wiki
ULA checks out ok btw
Mark
Repair Guides. Spanish Hardware site.
WoS - can't download? Info here...
former Meulie Spectrum Archive but no longer available :-(
Spectranet: the TNFS directory thread
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
This would explain why the symptoms are so specific (and benign for a RAM failure), and would seem to rule out a multiplexer failure also?
B
zx-diagnostics - Fixing ZX Spectrums in the 21st Century (wiki)
Sinclair FAQ Wiki
Repair Guides. Spanish Hardware site.
WoS - can't download? Info here...
former Meulie Spectrum Archive but no longer available :-(
Spectranet: the TNFS directory thread
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)