stardot.org.uk

Right with less than a week to go, anything anyone wants me to bring?

Already bringing Issue 5 Atom board & keyswitches for JudgeBeeb.

Arcadian, do you still want those C64s I offered you, if so shall I bring them?

Anything else anyone wants me to bring along?

Cheers.

Phill.

JudgeBeeb wrote: ↑

Fri Nov 15, 2019 10:34 am

Prime wrote: ↑

Fri Nov 15, 2019 9:19 am

I have a few desoldered from a beeb keyboard that I could bring along next weekend if you want.

That would be really helpful if you could. I believe that you also offered to bring a bare Atom PCB for me to look at...

Yep will bring that too.

Cheers.

Phill.

I am now looking into whether I can design a hybrid key-switch footprint that will accommodate both a modern Cherry MX (or compatible) key-switch and an original (Issue 5) Atom key-switch. I think it may just be possible, but it will be tight. It would be helpful if I could inspect and take measure...

@Phill, Do I see correct that the 74LS245 is mounted under the 6502 ? Assume this is direct on the board ? Yep that's correct, direct on board, with 6502 in a socket round it. And can you run the video board with just the 6845 and not the SAA5050 populated ? Not tried that, but if you only run the ...

bprosman wrote: ↑

Tue Nov 12, 2019 10:21 am

If you like I can assist to make them in Kicad if Phill is ok woth that.

Absolutely fine with that

Cheers.

Phill.

Kicad can load eagle files and make the gerbers :) The free version of Eagle should also be able to make gerbers from those files. Available here : ftp://ftp.cadsoft.de/eagle/program/ Any version after 6.x should be good, and the 6.x and 7.x versions don't require an Autodesk login. Cheers. Phill.

Good luck with that, hope it gets resolved though some of your comparisons come close to invoking Goodwin.......

Cheers,

Phill.

I think this is difficult to answer. As a developer it might be good to separate the project parts; each program might have its own working directory and so the files are spread over your local disk. But from the end-user perspective it might be handy to have it all in one repository because they d...

Hi all, This question is about my DragonMMC project but could also for example apply to the Electron / Atom boards I have made too. I've had a request to publish the source for DragonMMC (which I am intending to do). However since this project consists of 4 parts Schematic/Board layout**, Code for t...

I started playing around with trying to replace the INS8154 with a 6522 , by wiring up a 6522 to the appropriate signals from my System 1 board. The main take-away from the experiment was that it works, but the NMOS version of the 6522 doesn't source enough current to light a (calculator-style) LED...

Might also depend on which browser you are using. I've just done the following on the H page, on Firefox (both android and windows). Clicked next page twice, then clicked on "Hunchback" then back. On android it displayed the first page on windows it displayed page 3. However if I refreshed on window...

I normally pick a pinout that makes routing the PCB easy. This can be an iterative process, swapping pins (in the schematic) where necessary to avoid tracks crossing. Once the PCB is routed, I update the .ucf file with the final pinout, make the fitter can fit the design. This really means designin...

What I've have found made by Schroff are eye-wateringly expensive. I'm sure there are loads of these chucked in skips every day but I don't seem to be able to find any! Or I'm looking for the wrong thing... The one I built my system clone in I bought from a (ametur) Raido rally, for a pretty reason...

Oddly I have Adblock Plus on my windows install here, both it and FF are up to date and not seeing the behavior you are. Maybe it's an ABP setting that's causing it.

Cheers.

Phill.

daveejhitchins wrote: ↑

Fri Oct 04, 2019 6:48 am

Dito . . . I have one of Dave Moore’s folding tables that I used last year - so another spare table.

Is there anyone on here that doen't have something of Dave's

Cheers.

Phill.

The glitching while drawing is normal but if the drawing stops, the glitching must be gone and may not have corrupted the screen. The glitching is caused by sharing the databus between CPU and videoprocessor. What I have noticed with my various video addon boards, is that if you get screen corrupti...

If it's any help Ian....... I use firfox (69.0.1) on windows 10 and am not seeing this all of the recent items on the MyEbay page are things I looked at recently and all computer related....Just tried on my SuSE linux machine (Leap 15.1, so latest release) and that's fine too..... ff version is 60.8...

It could probably be added to the other implementations, but there is less room in the firmware (because the disassemblers are larger). So some messing would be required. It might also be a little tricky to get a third output from the AVR for special(2) for the 6809's FIRQ. Is this something you ne...

Does the issue with tracing with interrupts enabled still stand? e.g. if an interrupt happens it will get traced? Would be usefull to be able to ignore ints whilst tracing. On the 6502 & 6809 this should be easy enough to do I guess as the current instruction is finished before the interrupt is take...

The electrolytic capacitors (marked *) may be replaced by any value in the range 10 to 47µF. They should be rated 10 Volts or greater. So the values are not really critical. Indeed and 22µf seems to be the most common, and is the middle of the range, so what I use if I need to chenge them. Cheers. ...

Please put me down for a full table friday to sunday please.

Cheers,

Phill.

Update: Hotel booked.

So what actually turned out to be the problem in the end ?
Bad ROM I'm guessing?

Well done anyway.

Cheers.

Phill.

Is it you that has the fancy Dataman-40Pro EPROM programmer? These can read 24-pin 8Kx8 ROMs (e.g. the NEC upd2364) which are compatible with the Atom ROM. So you could try reading the ROM. The 40Pro can indeed read upd2364s. However, I have the even more fancy 48Pro2C which whilst being compatible...

A 74LS393 is a dual 4-bit binary counter. These are easy to test if you have a breadboard and a slow clock (from a 555 timer say) and either a logic probe, ‘scope or a bunch of LEDs. Though in this case it's IC44 IIRC which is the divider from 4MHz -> 1MHz for the phi0 (phi-in) clock so checking th...

Ctrl-G does not work. This was something I noticed a while back; but thought I could address when I got the video working. There is normal looking activity on the address and data lines, so the 6502 is certainly doing something. But I will play around with RAM chips and the 6502 and report back. Th...

I'll try poking my Atom(s) with my Rigol tonight.....

I have the original transistors in one of them and BC548s in another, so there might be slight differences.

Cheers.

Phill.

Once I have the board working, we can look at what features people would be interested in. One thing I have been thinking about is whether it is possible to design a single footprint that could take either a Cherry MX key-switch or an original Atom key-switch. Having said that, was it not the case ...

CMcDougall wrote: ↑

Tue Sep 24, 2019 4:47 pm

/\ only in dos window, from Start >cmd.com or exe can't mind which.

am lazy & use winXP as it does not have updates every 2hrs

EDIT, now on win10 lappy, it says "ask vendor for 64bit version"

If it's a DOS program then you could use Dosbox to run it.

Cheers.

Phill.

It has HiBASIC3 is ROM bank 8, shouldn't this auto load at startup? How can I disable BASIC4 in bank 12 and boot into HiBASIC in bank 8? Isn't there a *CONFIGURE option on the master to select the language ROM? Something like *CO. LANG 12 (can't remember if it has to be hex, in that case use C). Go...

Just like to add mine (and Lesley's) voice to the thanks to Jason (jnbeeb), everyone who attended and of course the museum for hosting us. Even if I did induldge in the 'treats' a little too much on saturday night

Look forward to next time.

Cheers.

Phill.