All-day 'Virtual' Acorn session #6, Saturday 1st August 2020, 9am - 11pm [NOW FULL!]

[klintworth]

Ok, me please!! I'm on holiday but will have wifi (and wife's blessing!) Thanks, Paul
(Will be on Mayne Island in sunny British Columbia, Canada!)

[Arcadian]

Nice one Paul you grabbed the last spot!

All 50 places now taken!

[waltermixxx]

will it be recorded? (you can record with zoom) I wish I had seen this sooner, Being in Canada,
i have always wanted to attend one of these. I would love to see the zoom recording afterwards
maybe posted on youtube?

Cheers. .

[Arcadian]

Yes, provided the presenter is happy for their talk to be recorded, barring any technical problems, the videos will get uploaded to the ABug.org.uk website, usually within a week of the event. An index of all recorded videos to-date is available here.

Regarding the 1st August event, we'll add you to a reserve list and should a space become free, we'll drop you a PM on Friday with login details.

[daveejhitchins]

July 1989 page 18

It’s not the best scan. If needed I will try harder tomorrow

Thanks, Roland . . . I've not seen that article - Interesting read. Looking forward to his talk this coming Saturday.

No need to rescan.

Dave H.

[Arcadian]

Here is a summary of all bar one of the activities/presentations/demos on Sat 1 August (the summary for ld-decode will follow soon!). Edit: ld-decode talk details now added.


Session 1 - Morning

9:45 - 10:45
Surgery (The A Team)

• <no assistance requested as of yet - please post in this thread if there is something you'd like the A-Team to help you with!>

11:00 - 12:00
JAFA Systems - upgrades for the Acorn Electron, presented by iwasjafa (John Wike)

For my talk, I was thinking along the lines of a potted life history:

• Life before JAFA (including writing microprocessor construction articles for electronic magazines)
• The JAFA years (products, such as the Electron Mode 7 adaptor, as well as technical details ... if I can remember them! )
• Post JAFA (including current interests and developments)

Session 2 - Afternoon

13:30 - 14:30
jsatom: Acorn Atom emulator in a browser, by CommanderCoder (Andrew Hague)

I intend to cover:

• My motivation for the emulator
• Learning JSBEEB
• Learning about the Acorn Atom
• Easy things (6502, pasting text and PPIA)
• Difficult things (tape, 6847 and 1-bit sound)
• Extra things (MMC for lots of software)
• What's next (combine with JSBEEB, SID chip)
• What's not next (Floppy Disc emulation)

15:00 - 16:00
How I make games for the BBC Micro by Tricky (Richard Broadhurst)

I'll likely cover:

• What makes me decide to write a game
• How I get the graphics and redormat them
• How I get the sound and convert to SN76489
• What build environment do I use
• What happens when I get sidetracked
• Why my games look a little different
• If there is time, what other tricks do I have up my sleeves

16:30 - 17:30
Micro-soldering demonstration by JudgeBeeb (Robert)

I am not holding myself out as any particular expert. The idea is to run through the kit and techniques I use, with a view to prompting discussion and encouraging others to give micro-soldering a try.

I will be screen-sharing my microscope camera, so people can see exactly what I am doing (assuming the technology behaves itself)

I will be soldering one of my BeebOPL Nano boards and I hope to demo the soldering of:

• 0402 passives
• 0.5mm pitch leaded ICs
• 0.5mm pitch leadless ICs

Session 3 - Evening

19:15 - 20:00
High Score Challenge, coordinated by KarateEd (Ed)


20:00 - 21:30
Domesday 86 - Part 2: ld-decode (Chad Page & Simon Inns)

As I mentioned during the last talk, this one will be all about the magic of ld-decode with an in-depth dive into the world of LaserDiscs, how they work and what it takes to build a software defined player. The original inventor of ld-decode, Chad Page, will also join me (from sunny California) to give a live demo processing a Domesday AIV disc image.

Here's the outline:

• Introduction to PAL LaserVision
  - The physical construction of a LaserDisc
  - How LaserDisc contents are encoded
  - From disc to laser… How a LaserDisc is played
• Sampling the Laser RF with the Domesday Duplicator
  - Component parts
  - Filtration
  - Some notes about the dreaded “Laser Rot”
• How a LaserDisc player functions after the laser bit
• Video
  - The Anatomy of LaserDisc video
  - PAL signals
  - Time Base Correction
  - VBI and VITS
  - Drop-out detection and correction
• Analogue Audio
• Digital Audio and Data
• Summary
  - Better than RGB capture?
  - The tool-chain
• Live demonstration of Domesday LaserDisc decoding

21:45 - 21:55
Micro-soldering update by JudgeBeeb (Robert)


22:00 - 23:00
POST box display adapter and A3000/A5000 restoration by myelin (Phil Pearson)

I'll be talking about my somewhat obsessive repair (~100 wires soldered, ~12 chips replaced) of an extremely damaged A5000, the incidental repair of three A3000 motherboards, and all the things along the way that made it possible:

• philpem's rediscovery and investigation of the RISC OS POST routines, and the CPLD based display hardware he made to access them
• My extension of this work to create a USB interface to allow scripted access to target machine registers and memory
• Experiences fixing RAM using the POST results: disabling the onboard ram on an A3000, and replacing/upgrading the A5000's memory using an old 4MB SIMM
• Experiences fixing IOC and VIDC failed errors (none of which were caused by failed IOCs or VIDCs, but rather broken tracks and bad latches).

[anightin]

• <no assistance requested as of yet - please post in this thread if there is something you'd like the A-Team to help you with!>

Dear All,

Since you ask

I have built an external voltage supply and a pin remapper for adapting 2532, 2716 and 2732 EPROMs for the TL866 programmer based on designs orginally from Chris Oddy and Volker Bosch.

http://theoddys.com/acorn/

My implementation is as follows:

TL866Adapter.pdf

(136.34 KiB) Downloaded 145 times

I've tested out the switching circuit independently using a bench supply with an input of 5v on the step-up side. Any output from the programmer over 15v (using another input from my bench supply) switches in the stepped up voltage that can be adjusted using the VR. There is adjustment enough from 12-25v on my setup that will goes to the EPROM.

You can also bypass this switching circuit to apply the voltage direct to the EPROM with the programmer out of the loop.

In all cases the programmer and the board share a common ground.

Here it is running with the voltage switching and 'high voltage' circuit disabled i.e. the TL866II is providing the voltage as per normal operation:

Here's the rub then. My TL866II programmer refuses to program any devices I have using the supply voltage from my board -- either direct or switched. I didn't capture a screenshot of the error but basically it says 'Programming Failed' and there is a verify error on the first byte written.

This is the programmer I am using which has the latest firmware and software under Windows 10:

I am slightly suspicious of the programmer at this point as it comes up with the same error if you switch off pin detect and lift the VPP pin and feed it from a bench supply as suggested here:
https://www.youtube.com/watch?v=F9ADB7ImSwc


Things I need help/feedback on:

1) Is there anything obvious in my implementation that I've missed that would stop it from working?
2) Could it be that the modern TL866II with latest firmware and software be blocking my external voltage inputs by way of detection?
3) Would anyone be able to lend me some known good 2532 and 2732 parts I can try, as it may be that the parts I have tested are faulty?
4) Does anyone want a blank board to populate and try themselves?
5) Does anyone want to borrow the board I built (and the programmer) to see if they can spot anything obvious? Maybe try it on an older TL866A or C programmer instead?

Many thanks in advance

Andy



Update:

Continued on this thread

viewtopic.php?f=3&t=20095#p281504

[JudgeBeeb]

Things I need help/feedback on:

1) Is there anything obvious in my implementation that I've missed that would stop it from working?
2) Could it be that the modern TL866II with latest firmware and software be blocking my external voltage inputs by way of detection?
3) Would anyone be able to lend me some known good 2532 and 2732 parts I can try, as it may be that the parts I have tested are faulty?
4) Does anyone want a blank board to populate and try themselves?
5) Does anyone want to borrow the board I built (and the programmer) to see if they can spot anything obvious? Maybe try it on an older TL866A or C programmer instead?

Many thanks in advance

Andy

Andy, I think your instinct to be suspicious of the EPROMs themselves is well-founded. I bought a large number of 2532s from various sources and all but a few refused to program. I would happily send you a couple of the known good chips. But I would need them back as I have so few that work. Drop me a PM with your address and I will pop them in the post in the next few days.

[simoni]

I see that I'm missing a summary for the Domesday86 part II talk... As I mentioned during the last talk, this one will be all about the magic of ld-decode with an in-depth dive into the world of LaserDiscs, how they work and what it takes to build a software defined player. The original inventor of ld-decode, Chad Page, will also join me (from sunny California) to give a live demo processing a Domesday AIV disc image.

Here's the outline:

Introduction to PAL LaserVision
- The physical construction of a LaserDisc
- How LaserDisc contents are encoded
- From disc to laser… How a LaserDisc is played

Sampling the Laser RF with the Domesday Duplicator
- Component parts
- Filtration
- Some notes about the dreaded “Laser Rot”

How a LaserDisc player functions after the laser bit

Video
- The Anatomy of LaserDisc video
- PAL signals
- Time Base Correction
- VBI and VITS
- Drop-out detection and correction

Analogue Audio

Digital Audio and Data

Summary
- Better than RGB capture?
- The tool-chain

Live demonstration of Domesday LaserDisc decoding

[anightin]

Things I need help/feedback on:

1) Is there anything obvious in my implementation that I've missed that would stop it from working?
2) Could it be that the modern TL866II with latest firmware and software be blocking my external voltage inputs by way of detection?
3) Would anyone be able to lend me some known good 2532 and 2732 parts I can try, as it may be that the parts I have tested are faulty?
4) Does anyone want a blank board to populate and try themselves?
5) Does anyone want to borrow the board I built (and the programmer) to see if they can spot anything obvious? Maybe try it on an older TL866A or C programmer instead?

Many thanks in advance

Andy

Andy, I think your instinct to be suspicious of the EPROMs themselves is well-founded. I bought a large number of 2532s from various sources and all but a few refused to program. I would happily send you a couple of the known good chips. But I would need them back as I have so few that work. Drop me a PM with your address and I will pop them in the post in the next few days.

Thanks @JudgeBeeb, PM sent.

[waltermixxx]

Thank you, that would be great.

I will keep an eye on my messages.

Yes, provided the presenter is happy for their talk to be recorded, barring any technical problems, the videos will get uploaded to the ABug.org.uk website, usually within a week of the event. An index of all recorded videos to-date is available here.

Regarding the 1st August event, we'll add you to a reserve list and should a space become free, we'll drop you a PM on Friday with login details.

[Arcadian]

Thank you, that would be great.

I will keep an eye on my messages.

A couple of the attendees have advised that it's quite possible they won't be able to attend, but will be unable to confirm until Friday/Saturday, so rather than keep you waiting I've added you to the main attendee list, so you'll definitely receive the login details via PM closer to the time.

Even if we go 1-2 over I'm sure we can cope! (I suspect being in Toronto you'll only be joining for the evening session and part of the afternoon session anyway?).

[sydney]

The Tuesday night meeting has produced an item for the A-team:
Broken beeb. Issue 3 with broken psu spade, a rom board removed and blank screen with flashing cursor.

[Snuggsy187]

Hi all,
Sorry but I have to cancel !

Work has just decided to dump a whole weekend of maintenance downtime on me (been after this for 4 months, so can't really get out of it !)

Will await the videos with eager anticipation, particularly Trickys - especially the bit about getting distracted !

At least there's a cancellation waiting list, so someone can have my space !

Enjoy Saturday.

[IanS]

Can you add me to the reserve list. (I'll try and get a working microphone by the weekend)

[Arcadian]

@Snuggsy - gutted! :o I'll send you a PM in a bit re the Pooyan queries...

@IanS - have added you to the main list in place of Snuggsy

[Arcadian]

During the 16:00 - 16:30 slot (directly after Tricky's talk on BBC Micro games creation) we'll open up for any feedback on the latest work-in-progress build of Tricky's Moon Patrol conversion.

It supports the arcade colour palette via VideoNuLA, which is emulated within the b2 and b-em emulators.

An ssd disc image is available to download here.

Alternatively you can play it online via this link though you will only see the standard beeb palette.

Despite all the work that's clearly gone in to this so far, it should still be considered an 'early' build, for example it's not yet possible to achieve a score.

I hope that as many attendees as possible can give the demo a whirl prior to Saturday - as feedback is a big motivator for game devs in terms of getting projects across the line and completed!!

Some notes from Tricky about the latest build below ...

Looks like it has been a year and a half since my last demo!
It still looks the same!
Keys are Z,X,SHIFT and RETURN.
NULA support is automatic.
The three tunes so far are 400 bytes + 200 for the player.
You can't die, but turn invisible while you are in a position that would kill you.
There are some graphical glitches and beebem is way off on timing.
No explosions, No car, No slopes, No rolling boulders, No alien patterns...

All feedback welcome, good or bad, it is all motivational.

P.S. Works well in jsbeeb

For comparison, the original arcade version of Moon Patrol can be played online here.

[BigEd]

(Feedback on the game presumably to be posted in the game's own thread)

[Chuckie]

I shall allocate to some dedicated time to solely beeb activities independently. At school I was the BBC Micro go to guy and mean from staff and pupils,
Ive got plenty of hard ware software projects going on plus got to photo graphs lots of lovely stuff. Enjoy.

[Soruk]

At school I was the BBC Micro go to guy and mean from staff and pupils

I found myself in that position for our room of BBC Masters. After the second time being called out of class to help when someone switched on the computer with a book on the keyboard (R+power-on, anybody?) I made myself a bootable ADFS disc with a string of *CONFIGURE commands to put the machine back to its intended state. Surprisingly, the teacher didn't want a copy.

[Arcadian]

Note we are switching to the #abug-chat channel on the Stardot Discord Server for live text chat during actual presentations at Virtual ABug events. More info here. This only applies whilst presentations are ongoing - Zoom text chat will be renabled during the gaps between presentations.

Also, another plea for participants to pre-create a Zoom account and set a profile image, as explained here.

Cheers!

[Kazzie]

I'm planning to offer repair advice during the a-team session, but as it turns out I'd also be glad to receive some, with regard to the RiscPC that I'm trying to repair.

Its major fault is a non-functioning VIDC, (Virq and Sirq errors in POST). These sympotms materialised a week or so after I'd repaired battery damage around the CMOS power lines; the faults may or may not be related.

As well as any direct advice, some baseline measurements from a working board and VIDC would be useful, as I've got no real benchmark other than guesswork and logic at the moment.

[Arcadian]

Ok I'll make a note in the A-Team section, but there are already two items to be covered in a one-hour slot ... possibly if you are online earlier (e.g. from 9am) we can put it to any other Arc/RISC PC gurus that may already be online then. If not possibly we could look at it after Myelin's late talk (which ironically is about Archimedes restoration)...

Failing that, there's the Tuesday evening technical sessions, the next one being 11th August.

[sydney]

PM's with the meeting details have been sent. Please let me know if I missed you out.

[Arcadian]

Just an FYI, we will be alternating the role of the 'host' throughout the day and the schedule below should broadly reflect the timings ...

09:00 - 10.45
sydney (Simon H)

10.45 - 14:55
JudgeBeeb (Robert)

14:55 - 16:25
sydney (Simon H)

16:25 - 18:00
simoni (Simon I)

18:00 - 19:45
sydney (Simon H)

19:45 - 23:00
danielj (Daniel)

[Doctorj1]

As discussed on Tuesday, and previously mentioned by @sydney, my Beeb is having issues and has been logged for attention in the A-Team morning session.

Here is a picture of my Beeb board, which is currently booting up to a flashing cursor with no beep. I've also just taken off a Watford Electronics 12 ROM board (so there might be a problem with jumper settings).
I've yet to test it after soldering on the power connector inbetween IC32 and IC4, but I will just after posting this.

[steve3000]

I can rarely attend these due to family commitments at weekends and I expect probably too late notice, but I am now free tonight and if any evening spaces, or drop-outs, I'd like to attend Phil (myelin's) presentation...

[Elminster]

I can rarely attend these due to family commitments at weekends and I expect probably too late notice, but I am now free tonight and if any evening spaces, or drop-outs, I'd like to attend Phil (myelin's) presentation...

Will leave that to the admins to sort, but I won’t go to that particular presentation as I don’t know anything about acorns with more than 8 bits.

Perhaps there is some way to share a slot in future, for those of us who can do some slots but not others.

[Arcadian]

I believe sydney has pm'd steve with the zoom details (or is about to) ...

[cjm]

Hi,

I would like to join this afternoon's session if any spaces become available.

Chris.