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by dominicbeesley
Mon Jan 15, 2018 10:35 pm
Forum: hardware
Topic: BBC B Running slow
Replies: 8
Views: 285

Re: BBC B Running slow

I commented suspecting stray interrupts (of either flavour). But then I read the fault description again and deleted my comment. I'm struggling to see any way that stray interrupts would suddenly clear up the moment you entered BASIC! Unlikely but it could be all sorts of pickup most been motherboa...
by dominicbeesley
Mon Jan 15, 2018 4:53 pm
Forum: hardware
Topic: BBC B Running slow
Replies: 8
Views: 285

Re: BBC B Running slow

Has it had DFS in the past. If s9 is snipped it might be spurious NMIs. What other roms ate fitted?
by dominicbeesley
Fri Jan 12, 2018 9:02 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 35
Views: 880

Re: SpectROM - Speccy emulator for the Pi co-pro

Excellent work rob...another triumph
by dominicbeesley
Wed Jan 10, 2018 5:44 am
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

I'll have a go at hacking something together myself and let you know results before asking you to commit to anything. Even without DMA I need to work out if polling or NMIs would be better for block transfers. I'd say for a general purpose serial port some sort of disable-able interrupts would be in...
by dominicbeesley
Tue Jan 09, 2018 10:40 pm
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

I'm mega-busy this week so won't have a chance for any in-depth tests of speed on the serial link but I will think about this when I'm on holiday. I was going to have several transfer modes for the DMA 1) halt processor, seize the bus, transfer one byte in/out every cycle 2) NMI, trap NMI before cpu...
by dominicbeesley
Tue Jan 09, 2018 12:52 am
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

Thanks Simon. Much appreciated
by dominicbeesley
Tue Jan 09, 2018 12:47 am
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

Thanks Phil, I started experimenting around the same area. I first tried just removing the twiddly status register stuff in .ReadData itself: that didn't do anything noticeable but I've not been measuring accurately (counting cursor flashes while as ~96K module loads in 5 chunks). I see what you're ...
by dominicbeesley
Mon Jan 08, 2018 11:40 pm
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

I'd vote drop anything that is JIM / PAGE FD related, as unearthed in a recent thread JIM is broken and two devices can't really share it. If you could get two COM ports working that would be worth more to me than anything else! I've had a quick test this past hour and it seems to work well (barring...
by dominicbeesley
Mon Jan 08, 2018 8:00 pm
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

Aha. I'll try TAB later.

No the serial port has been pretty straightforward. Thus is running the perl server under Cygwin.

Do you know is there any way of getting two usb com ports on those uControllers? Having hostfs and noIce at the same time would be immense!
by dominicbeesley
Mon Jan 08, 2018 7:24 pm
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

Woo hoo!

20180108_191810-s.jpg


Got to cook tea, more later hopefully!

D

PS: How do I select on break? U,H don't seem to work
by dominicbeesley
Mon Jan 08, 2018 6:04 pm
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

Hi Phil,

I just gave it a quick shot. I recompiled UPURSFS with the new locations but I just get "UPURSFS no selected; no RTS" is there other stuff I need to disable/enable?

D
by dominicbeesley
Mon Jan 08, 2018 11:33 am
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

cmorley, interesting! I need to look at that...
by dominicbeesley
Mon Jan 08, 2018 10:50 am
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

Thanks Phil, the driver for the debugger is quite larges (about 3 and a half pages, plus some buffer space). I'm not sure where best to put it, I may come up with a few different versions. The simplest would just become the current language and place itself in 400-700 plus wherever I can fit the res...
by dominicbeesley
Sun Jan 07, 2018 8:24 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

A little progress on this. I've separated out the DMA controller, blitter and sound chip into 3 logical chips. In the 6809 version these will be 3 separate physical cplds, on the beeb plug in I may use a newer cpld and cheat with them all together in one max10. I now have the dma controller working....
by dominicbeesley
Sun Jan 07, 2018 8:02 pm
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

I've still not tried the SD adaptor yet but the serial port is brilliant! I got half an hour earlier and hacked together a driver for the very useful NoIce debugger . At 19,200 this was usable but a bit hesitant when single-stepping with a lot of watches set up, now even when its fetching a load of ...
by dominicbeesley
Wed Jan 03, 2018 1:22 am
Forum: hardware
Topic: Fast serial port/SD card adapter for the 1MHz Bus
Replies: 25
Views: 937

Re: Fast serial port/SD card adapter for the 1MHz Bus

A quick update - and kudos to Phil (myelin). I finally got my boards from California on the second attempt, the first lot got lost, not helped by my giving phil the wrong postcode! I got the solder station out this afternoon and put the thing together. So far I've only tried the serial port and it i...
by dominicbeesley
Sun Dec 31, 2017 4:36 pm
Forum: hardware
Topic: Playing with the SAA5050
Replies: 14
Views: 785

Re: Playing with the SAA5050

I'm not sure I started experimenting with this when I was messing around with mode 7 / 80 cols earlier this year. I suspect that its something to do with spurious control chars upsetting the start of the next line? It might be only on certain saa5050s? I didn't see any need for it so left it off the...
by dominicbeesley
Sun Dec 31, 2017 4:30 pm
Forum: hardware
Topic: What are these called?
Replies: 15
Views: 516

Re: What are these called?

You "can" but I wouldn't for anything that I'm sending to somebody else. The square profile pins are a bit fatter than the smaller turned pins and tend to overbend the contacts in IC sockets rendering them unreliable on normal chips. I've spent a lot of time trying to fix beebs that turned...
by dominicbeesley
Thu Dec 28, 2017 2:27 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

Thanks lads, atcurtis, I'm not sure what you mean do you mean will it handle the '12 in a master or enable putting a '12 in a model B? I'm looking at both possibilities (as well as other possibilities) jregel, at the moment the sound comes from a 1-bit dac with a simple resistor / capacitor filter t...
by dominicbeesley
Wed Dec 27, 2017 10:42 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

I've spent some time making an assembler protracker player. It does more effects but is by no means complete. It looks to me like it would be possible to have something like this running off interrupts during a game without eating too many cycles.... Anyway, I'll get back to hardware designing now, ...
by dominicbeesley
Fri Dec 22, 2017 10:25 am
Forum: hardware
Topic: RIFA'd again
Replies: 6
Views: 453

Re: RIFA'd again

Ha. That smells gettin hintense
by dominicbeesley
Wed Dec 20, 2017 9:49 pm
Forum: hardware
Topic: S9 Jumper
Replies: 9
Views: 323

Re: S9 Jumper

Or maybe it does....I've not got a working beeb with a real 6502 but the one with a T65 vhdl 6502 hangs if NMI is low at reset. A second press of Break clears it though!

D
by dominicbeesley
Tue Dec 19, 2017 6:07 pm
Forum: hardware
Topic: S9 Jumper
Replies: 9
Views: 323

Re: S9 Jumper

It shouldn't matter as NMI is edge triggered so a weak pull up should work and not draw too much current. I'm pretty sure the 6502 doesn't do anything too crazy if NMI is asserted at reset....
by dominicbeesley
Tue Dec 19, 2017 10:42 am
Forum: hardware
Topic: S9 Jumper
Replies: 9
Views: 323

Re: S9 Jumper

It should be jumpered/linked otherwise there may be spurious NMIs. Mostly spurious NMIs are relatively harmless as they are edge triggered i.e. if it floats high or low you will only get one. Also, there is usually an RTI at D00 which means that the machine doesn't crash it just slows down a little ...
by dominicbeesley
Sat Dec 16, 2017 1:03 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

Thanks, I'm quite surprised that it worked at all! Each sound channel (there are 4) plays at an independent rate any from 53 samples per second to around 100000 samples per second. Each channel has a 16 bit divider (I may reduce this to 12 bits to save chip space) to set the sample "period"...
by dominicbeesley
Fri Dec 15, 2017 7:28 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

http://www.youtube.com/v/-EIi6XHRU0M?hl=en&fs=1 https://youtu.be/-EIi6XHRU0M Apologies for the crap sound quality and bad sync, having phone problems Thought I'd give it a go, a quick tracker player in BASIC with a small shim of assembler to quickly set registers. No effects or anything fancy.....
by dominicbeesley
Tue Dec 12, 2017 2:29 pm
Forum: software: new games
Topic: New Release: Retro Software's WHITE LIGHT by Sarah Walker
Replies: 55
Views: 2486

Re: New Release: Retro Software's WHITE LIGHT by Sarah Walker

Can you satisfy my curiosity? Is Sarah Walker a real person or is it a fictitious name that identifies a development group? I think I'm a real person, at least... Really? I suspect you must have some super-powers! This is a most impressive accomplishment. I almost feel like giving up! You must have...
by dominicbeesley
Tue Dec 12, 2017 1:15 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

Thanks lads, Got you Rob. I've been ironing out bugs with the sound accesses causing pixels/bytes to drop out when copying which turned out, after about 12 hours of rewriting the state machines, testing, building probe circuits to be a "bodge" I'd put in to test something else and not remo...
by dominicbeesley
Sat Dec 09, 2017 12:23 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

The reason for four independent channels with their own sample rate is that polyphonic sample playing then becomes pretty simple i.e. it should be possible on the beeb to play simple tracker/mods. A couple of fixed rate channels however would require a lot of processing power to do anything like tha...
by dominicbeesley
Fri Dec 08, 2017 12:07 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 49
Views: 2197

Re: A blitter for the beeb?

Thanks for the info Thomas, I'd not considered the Lynx, I didn't know it used a blitter, I thought they were sprites. Interesting stuff about interrupts, at the moment my blitter isn't interruptible but will be I was going to restart the blit on the first RTI but not sure that that will work as I s...

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