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IORQ active, others not active
Score: 138.87 %,
Type: Forum topic , Comments: 2 comments
I am experimenting with my machine, and it appears to have IORQ active for long time - at least 280 ns, with RD and WR being inactive. I can not have picture of M1, because it is just not routed to the board.
However M1+IORQ situation is only possible (according to Z80 manual) in IM0 mode as interrupt ...
Batch 4 of GR8NETs is ready for distribution
Score: 138.74 %,
Type: Forum topic , Comments: 7 comments
Please contact me for more information - and see manual here .
Are there any hardware Are there any hardware differences between the 4 batches?
The only difference is that The only difference is that from batch 2 on there're ...
HB-501P (MSX1) port I/O issue
Score: 138.24 %,
Type: Forum topic , Comments: 17 comments
(+5V) or down (0V) but hardware that uses open collector logic can only drive the bus down or leave ... Without this the state will be most probably floating somewhere between 0V and +5V computer can see it as bit 0 or 1 depending of what color socks you are wearing.
It is indeed true that adding 10K ...
Identify if BASIC text is variable or constant/formula
Score: 137.97 %,
Type: Forum topic , Comments: 2 comments
I need to organize input/output from assembler program into same variable. For example, CALLFUNCTION(A,B,C). But it also can be CALLFUNCTION(,,C) or CALLFUNCTION(1,2,3). Is there any safe way to check if text pointed to is variable (e.g. "A") ...
Zemmix Neo (and probably OCM) issue
Score: 136.11 %,
Type: Forum topic , Comments: 17 comments
(0.5 T-cycle) after IORQ activates and ends with IORQ;
WR: port data write
Situation is the same as with port read: for OCM activtion of WR signal is delayer by 0.5 T-cycles.
My ... write 0.5 T-cycles later than Z80.
MSX cardridge port signals MSX cardridge port signals ...
