UE1-UE6 2114 or TMM314A SRAM MEMORY
Blank screen. Partial failure: less than normal "3583 BYTES FREE" at
startup, sometimes will produce "garbage" screen or screen freeze after
warmup. Shorted chips may get very hot. NOTE: UE1 is used to generate
character color.
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Last edited by mrr19121970 on Thu Apr 21, 2016 12:12 pm, edited 2 times in total.
Normally, I'd want to know whether it is a 2-prong or DIN plug VIC-20, but in this case, it's irrelevant: the colour RAM is UE1 in both PCB revisions.
Indeed it appears as if bit 2 (value 4) is 'shot' (i.e. stuck at 0) for some of the nibbles. In a similar fashion (blue -> red), yellow should turn to cyan in some places, green to white, and purple to black.
Mike wrote:
Indeed it appears as if bit 2 (value 4) is 'shot' (i.e. stuck at 0) for some of the nibbles. In a similar fashion (blue -> red), yellow should turn to cyan in some places, green to white, and purple to black.
This is exactly how it behaves....
I replaced UE1 with a socket, and tried both new chips. SAME issue. No chip = no colour
I don't know. I noticed the chars also were not always wrong. Typing an pressing delete sometimes corrected colour (or made colour wrong when correct before).
The WIKI troubleshooting guide was amended for this issue
