Search found 25 matches

by Stimpy
Fri Nov 16, 2018 7:40 am
Forum: ST 16MHz V2.X SERIES BOOSTERS
Topic: V2.5 BOOSTER CURRENT PROTOTYPE STATUS (SEC BOOSTER)
Replies: 448
Views: 51333

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS (SEC BOOSTER)

Top tip for routing RAM, you can pin swap data bits and some address bits depending on the type of ram used. Probably best just to stick to the data bits though to be on the safe side.
by Stimpy
Tue Nov 13, 2018 9:51 am
Forum: Terriblefire's channel
Topic: Terriblefire Accelerators
Replies: 221
Views: 22324

Re: Terriblefire Accelerators

ICs best routed direct to power and ground plane with as short as possible tracks, ideally via right next to pad. Then place caps in small package as possible, again with vias to decouple the plane. Place vias to side of caps for smallest inductance loop, imagine viewing the board if it was sliced ...
by Stimpy
Mon Nov 12, 2018 8:46 pm
Forum: Terriblefire's channel
Topic: Terriblefire Accelerators
Replies: 221
Views: 22324

Re: Terriblefire Accelerators

ICs best routed direct to power and ground plane with as short as possible tracks, ideally via right next to pad. Then place caps in small package as possible, again with vias to decouple the plane. Place vias to side of caps for smallest inductance loop, imagine viewing the board if it was sliced a...
by Stimpy
Sat Oct 27, 2018 1:46 pm
Forum: HARDWARE DISCUSSIONS
Topic: BLITTER RE-CREATION THOUGHTS
Replies: 228
Views: 29228

Re: BLITTER RE-CREATION THOUGHTS

Perhaps my old post wasn't clear, but with all suska cores you choose if you want your buffers internal or drive external ones. There are two top files in the hierarchy. You dont need to modify anything apart from your pin constraints file to put signals on your pin of choice. So are you saying the...
by Stimpy
Sat Oct 27, 2018 10:26 am
Forum: HARDWARE DISCUSSIONS
Topic: BLITTER RE-CREATION THOUGHTS
Replies: 228
Views: 29228

Re: BLITTER RE-CREATION THOUGHTS

I've used an IDT part in the past, for floppy etc but can't remember which one.it was bidirectional. However the TI parts have very good documentation, so might be better choice. Most seem to be based on the MOSFET idea, which I've also used in discrete form for I2c etc. Perhaps my old post wasn't c...
by Stimpy
Thu Oct 25, 2018 8:32 pm
Forum: HARDWARE DISCUSSIONS
Topic: BLITTER RE-CREATION THOUGHTS
Replies: 228
Views: 29228

Re: BLITTER RE-CREATION THOUGHTS

If we did not have to worry about tri-state, then pretty much any general logic level translator chip would work. In case of the blitter, it needs to be tri-stated and it does not have control logic in the core to take care of that The suska code does if that's what you mean? My post from 14th sept...
by Stimpy
Thu Oct 25, 2018 8:29 pm
Forum: HARDWARE DISCUSSIONS
Topic: BLITTER RE-CREATION THOUGHTS
Replies: 228
Views: 29228

Re: BLITTER RE-CREATION THOUGHTS

The 5v you see on the pin is probably just leakage current and the tiny ESD diodes inside the FPGA will just clamp that, it'll be microamps.
by Stimpy
Sun Oct 21, 2018 7:18 pm
Forum: TWEAKS & FIXES
Topic: Hissing and whistling in the STe audio output
Replies: 112
Views: 14683

Re: Hissing and whistling in the STe audio output

Is it an anti alias filter or something? Perhaps the clock driving it needs to be series terminated? Or maybe its just a noisy chip?
by Stimpy
Fri Sep 28, 2018 8:45 am
Forum: ALPHA DEVELOPMENT INFO
Topic: Video driver thoughts
Replies: 272
Views: 19259

Re: Video driver thoughts

I used a falcon video DAC when I did my ST, as it was what i had kicking about. It worked off 32MHz in all resolutions. I just used the MSBs and tied lower bits to ground like any DAC or ADC. I do remember it getting pretty hot though, it was mounted with kynar wire to stripboard so no real thermal ...
by Stimpy
Mon Sep 17, 2018 2:30 pm
Forum: RTC (Real time clock)
Topic: FALCON 030 RTC (2017 Batch)
Replies: 26
Views: 6730

Re: FALCON 030 RTC (2017 Batch)

I had a similar experience with a customers Falcon, replaced the NVRAM and it didn't boot. Put original back in and it was OK. I seem to remember it wouldn't even attempt to load from floppy so I had no chance getting that autobooting disk to work. I do remember fixing it by trying all the different...

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