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+--- Thread: Joining the even cooler kids: Premium 128K (/thread-550.html)
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RE: Joining the even cooler kids: Premium 128K - CheshireNoir - 20-08-2022
Hey folks,
Does anyone have the pinout of the DB9 video port on the Premium?
I need to make up a small cable to interface for my CGA to VGA adapter and I just need to know which pins go where.
Cheers!
John
Never mind. It looks like a standard CGA signal after all.
I've now got it booting. I think there's a RAM issue as stuff that fits in 56K seems fine. Testing with the RAM test ROM shows issues with Bank 2. Bit 5 seems "stuck".
Off to the schematics, Batman!
John
RE: Joining the even cooler kids: Premium 128K - Ernest - 21-08-2022
Hi John,
Check IC 9 - this should be bit5 of the Bank2.
Ernest
RE: Joining the even cooler kids: Premium 128K - CheshireNoir - 21-08-2022
Thanks Ernest. I'll do that when I get to that stage. For now I want to concentrate on the keyboard.
I think I'll follow the design made by @Suzy over at the other forum, and make Cherry to Microbee adapters.
(I've PMd Suzy here, so hopefully she'll get back to me. I can always recreate her board design but why reinvent the wheel if I don't need to?)
In the meantime, I made a thing! :-)
It's a new, neater PSU just for the DRAM systems. It's got a tap to drive a Gotek and uses a DC to DC adjustable converter to bring the voltage down to a useable range. (Currently set to 10v, but I'll slowly drop it to closer to 9 so the 7805s don't get so hot)
John