Skip to first unread message
Mark T
Jul 11, 2019, 1:56:34 AM7/11/19
to retro-comp
Hi Tadeusz,
I don’t have any experience with z280, other than in 1990 when we replaced an 8085 board in an in house designed piece of test equipment with a z280 because we ran out of eprom space. Too long ago to remember anything useful and we used z80 bus mode anyway.
I was interested in your draft because at some point i’d like to experiment with a sixteen bit bus and your draft is quite similar to the existing z80 bus. I’m still undecided on processor, either z280 or 68332, but i think it raises similar questions.
For memory, were you intending to include this on the processor module or on a separate module to allow a larger memory using sram? Have you thought about using two bytewide memory modules instead of a single wordwide module? Maybe only populate the header pins for D0-D7 or D8-D15, for high byte or low byte memory.
Do you think its possible to use the zbus to connect existing input/output modules? Just wondering how this might work for byte addressing when even or odd addresses use a different half of the data bus. Maybe a bidirectional buffer between high and low byte of the data bus might be possible.
Mark
I don’t have any experience with z280, other than in 1990 when we replaced an 8085 board in an in house designed piece of test equipment with a z280 because we ran out of eprom space. Too long ago to remember anything useful and we used z80 bus mode anyway.
I was interested in your draft because at some point i’d like to experiment with a sixteen bit bus and your draft is quite similar to the existing z80 bus. I’m still undecided on processor, either z280 or 68332, but i think it raises similar questions.
For memory, were you intending to include this on the processor module or on a separate module to allow a larger memory using sram? Have you thought about using two bytewide memory modules instead of a single wordwide module? Maybe only populate the header pins for D0-D7 or D8-D15, for high byte or low byte memory.
Do you think its possible to use the zbus to connect existing input/output modules? Just wondering how this might work for byte addressing when even or odd addresses use a different half of the data bus. Maybe a bidirectional buffer between high and low byte of the data bus might be possible.
Mark
Reply all
Reply to author
Forward
0 new messages