Search found 4855 matches

by MartinB
Wed Aug 15, 2018 7:00 pm
Forum: hardware
Topic: Converting ABR to EEPROM (28C256) for the Master
Replies: 19
Views: 451

Re: Converting ABR to EEPROM (28C256) for the Master

Could you repeat but load a different image into each slot so that the two slots aren’t the same. Include the second Elk confirmation before moving to a Master.
by MartinB
Wed Aug 15, 2018 6:17 pm
Forum: hardware
Topic: Converting ABR to EEPROM (28C256) for the Master
Replies: 19
Views: 451

Re: Converting ABR to EEPROM (28C256) for the Master

What makes you sure that both images have been loaded on the Elk in the first place? Your video shows the program asking to load the ABR and then showing slots 2 & 3 with the ABR utils but do you actually check off-video that each has the image physically loaded? I’m guessing that one of the two slo...
by MartinB
Wed Aug 15, 2018 7:45 am
Forum: hardware
Topic: Rrad only 8271!
Replies: 6
Views: 169

Re: Rrad only 8271!

I notice that in the Beeb, WR on the 8271 is pulled high quite aggressively with a 150 ohm resistor. I’ve always wondered why certain signals on certain chips require such a low value when normally, pull-ups tend to start in the lower k ohm ranges. Does this suggest that signals such as WR on the 82...
by MartinB
Mon Aug 13, 2018 8:36 pm
Forum: hardware
Topic: Converting ABR to EEPROM (28C256) for the Master
Replies: 19
Views: 451

Re: Converting ABR to EEPROM (28C256) for the Master

On the softlock, as soon as I discovered this quaint eeprom feature, it sounded really cool so I just dived straight in and added the tools but this was before I encountered the now notorious ‘write-offline’ quirk that was tending to hang Acorn kit. So, even though I later mandated a hardware write-...
by MartinB
Mon Aug 13, 2018 7:45 am
Forum: hardware
Topic: Converting ABR to EEPROM (28C256) for the Master
Replies: 19
Views: 451

Re: Converting ABR to EEPROM (28C256) for the Master

Just need to persuade Martin to alter his great EEPROM utilities to do this for the Master: Remove ROM from ROM table : Unlock ABR : Load image into ROM : Lock ABR : Read ROM type and insert into ROM table . . . Magic . . . :- So would that be a new independent utility in the set or a change to *EE...
by MartinB
Mon Aug 13, 2018 7:33 am
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Heh heh =D>
by MartinB
Mon Aug 13, 2018 7:23 am
Forum: hardware
Topic: UPURS cable and rom ?
Replies: 11
Views: 297

Re: UPURS cable and rom ?

Hello Andrew - no idea if I’m real or not :-k but I’ll send you a PM with my email address and you can ping me on there. In essence, I can provide an UPURS cable and rom but I’m away on hols at the moment so you’re looking at two or three weeks lead-time I’m afraid. There are already two orders queu...
by MartinB
Sun Aug 12, 2018 10:24 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Don't be silly Duncan, it's not a squiggle snake, it's clearly a spring.... :roll: Thanks again Mark, that of course answers the Master query. The higher effective value isn't actually going to be a problem but it is valuable information for me to be aware of. No need for any more testing then folks...
by MartinB
Sun Aug 12, 2018 8:21 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Ok, thanks Mark. Maybe you’ve previously robbed the 6522 from that Master for another fix because it’s almost as if it doesn’t have one fitted! 😜
by MartinB
Sun Aug 12, 2018 7:57 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Mark - first off, I also have the excellent DT-4000 and a Fluke (the respected Model 12) and the two always read close enough for the delta not to matter. All the Beebs look as I would expect, we’re just seeing the tolerance of the external 10k pull-ups working in parallel with the 6522 internal pul...
by MartinB
Sun Aug 12, 2018 4:59 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Wow! 😳

Thanks Mark! I’ll have a digest and comment later....😎
by MartinB
Sun Aug 12, 2018 2:37 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Thanks also Richard and Duncan, that’s great...👍🙂

I’ll explain in due course....😉
by MartinB
Sat Aug 11, 2018 11:58 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

That’s brilliant, thanks Adrian... =D> :D

So your 6522 has internal pull-ups of roughly 1.2k ohms which is what I think I originally measured on some of mine.

Thanks again 8)

(Any other samples would be interesting if anyone has a bored moment to spare.... :wink: )
by MartinB
Sat Aug 11, 2018 10:08 pm
Forum: hardware
Topic: UPURS cable and rom ?
Replies: 11
Views: 297

Re: UPURS cable and rom ?

Without Farcebook, apparently nobody.....
by MartinB
Sat Aug 11, 2018 10:00 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Yes, because of the 6522 having what I believe from previous testing to be an internal ~1k pull-up to 5v on the data lines. It's just something that I would check on a few Beebs if I was at home but being away, the thought is niggling me. If it is as I suspect, then the 10k's have actually reduced t...
by MartinB
Sat Aug 11, 2018 9:49 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Please don't go to any trouble, it's certainly not urgent - I was just trying to settle a collection of project thoughts in my head. Anytime in the next few days will be fine... 8)
by MartinB
Sat Aug 11, 2018 9:32 pm
Forum: hardware
Topic: UPURS cable and rom ?
Replies: 11
Views: 297

Re: UPURS cable and rom ?

Oh, did I not make that clear....? :lol:
by MartinB
Sat Aug 11, 2018 9:31 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Re: Quick measurement

Yes, and I think Pin 1 is top right but there are also probably little moulded numbers in the plastic. A straightened paper clip might fit the sockets....?

( For orders of magnitude btw, I'm thinking about 900 ohms ? )



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by MartinB
Sat Aug 11, 2018 9:00 pm
Forum: hardware
Topic: Quick measurement
Replies: 28
Views: 359

Quick measurement

I'm on holiday and away from my Beeb stuff so if anyone has a Model B and a DMM handy and could do a quick couple of measurements for me, I would be most grateful. It's just two power-off passive resistance checks on the analogue (joystick) connector, between the the two fire button inputs and the +...
by MartinB
Sat Aug 11, 2018 8:20 pm
Forum: hardware
Topic: UPURS cable and rom ?
Replies: 11
Views: 297

Re: UPURS cable and rom ?

He can poke this on his wall tag.....


poop.jpg
poop.jpg (4.49 KiB) Viewed 227 times

:D
by MartinB
Sat Aug 11, 2018 8:16 pm
Forum: hardware
Topic: Converting ABR to EEPROM (28C256) for the Master
Replies: 19
Views: 451

Re: Converting ABR to EEPROM (28C256) for the Master

To be honest, I didn't ever do much intelligent investigation into the Master internal eeprom fit - when it wasn't playing ball, I pretty much just retreated to the cartridge solution, not least because there isn't actually that much rom real-estate inside a Master and after all, cartridges are ther...
by MartinB
Sat Aug 11, 2018 3:08 pm
Forum: hardware
Topic: UPURS cable and rom ?
Replies: 11
Views: 297

Re: UPURS cable and rom ?

Paul, who owns RetroKit, has been a little poorly in recent times and “the UPURS guy who developed it” doesn’t have (and has never had) a Farcebook account, let alone a “channel”! You should maybe send him a PM on here....



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by MartinB
Sat Aug 11, 2018 2:43 pm
Forum: hardware
Topic: Converting ABR to EEPROM (28C256) for the Master
Replies: 19
Views: 451

Re: Converting ABR to EEPROM (28C256) for the Master

I’m on hols Dave as you know but quickly, I didn’t ever get my eeprom stuff working in a Master internal socket but everything was fine in a cartridge. That’s probably no help whatsoever but just thought I’d mention it...😜


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by MartinB
Tue Aug 07, 2018 8:36 pm
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

Pretty much, except no hand pump - just a bucket on a rope......
by MartinB
Tue Aug 07, 2018 8:26 pm
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

So if you're actually looking to get things done rather than mess around trying to optimize your build pipeline, using standard UPURS is an excellent idea. Ha! It’s important to point out that unlike many folk on here, I’m not from a computer or software background and so much of the stuff that peo...
by MartinB
Tue Aug 07, 2018 4:18 pm
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

Well, if you don’t mind a few weeks lead-in then I’ll sort the cable for you, and an UPURS v5 eprom if you need help with that too? (Although you can run nearly all the UPURS utilities from disc, the eprom is much more convenient for a development environment which is what this is all about.) I norm...
by MartinB
Tue Aug 07, 2018 11:36 am
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

I franchised-out the cable making to others on here because I constantly have Beeb-project bandwidth issues 🙄. I do still make the odd one and I wouldn’t see you stuck but just now I’m away on hols for a couple of weeks plus, I’m not convinced I have the D-types in stock so overall, if you need me f...
by MartinB
Mon Aug 06, 2018 11:01 pm
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

Yes, the one below has always been my recommendation because it’s based on the reliable FTDI chipset and importantly, like it’s partner UPURS, it also just works... =D> (Indeed, I developed UPURS from day one around this very adaptor.) http://www.tronisoft.com/shop/adaptors-connectors/usb-to-serial-...
by MartinB
Mon Aug 06, 2018 7:55 pm
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

(Also thanks to everyone else for the UPURs recommendation! That also looks like a good solution). It is, and it just works. Way better than all this modern temperamental twaddle.... :lol: (Also, with the built-in pseudo filing system UPCFS which replicates the CFS but at lightning speed, you can L...
by MartinB
Mon Aug 06, 2018 8:57 am
Forum: development tools
Topic: Deploy-and-run from PC to Beeb?
Replies: 26
Views: 472

Re: Deploy-and-run from PC to Beeb?

I develop on a PC, both standalone code proggies and sideways roms. I do exactly what you want to do using, perhaps predictably, UPURS and specifically using UPLOAD which simply allows you to do a *LOAD directly from the PC, albeit via a cable.