If you have connected C21 the wrong way round then be aware that electrolytics can be damaged by doing so. You may need to replace it again.
Alan
Search found 131 matches
- Tue Jan 26, 2021 8:41 am
- Forum: 8-bit acorn hardware
- Topic: No -5v after recap
- Replies: 26
- Views: 1199
- Sat Jan 23, 2021 3:40 pm
- Forum: programming
- Topic: Trick MODE changes
- Replies: 1
- Views: 214
Re: Trick MODE changes
It's fairly simple to do - in fact quite a few commercial games do it during their loading phases. On the Model B most of the short MODE code is lifted from the ROM with a few other instructions added. On the Master it's trivial: lda #$16 jsr oswrch lda #(mode+128) jsr oswrch lda #$70 ldx #$01 jsr o...
- Fri Dec 04, 2020 2:57 pm
- Forum: 8-bit acorn hardware
- Topic: Model B Issue 7 continuous beep at boot / RAM issue
- Replies: 24
- Views: 715
Re: Model B Issue 7 continuous beep at boot
viewtopic.php?f=3&t=16006&p=220996#p220996Lardo Boffin wrote: ↑Fri Dec 04, 2020 2:26 pmI am sure I have seen a reference to the minimum set of chips required for the beeb to boot. Anyone know the term for it and where I can find it?
Thanks!
- Thu Nov 19, 2020 10:21 pm
- Forum: 8-bit acorn software: other
- Topic: BBC Master - Calendar shows 1920 not 2020
- Replies: 11
- Views: 648
Re: BBC Master - Calendar shows 1920 not 2020
One of the first things I did on my Master was to program a TIMEFIX ROM to load into sideways RAM. https://stardot.org.uk/forums/viewtopic.php?f=2&t=12816 One advantage is that it stores the century in an unused byte in the configuration RAM, so it survives reboots. It was mainly done as an inte...
- Sun Oct 18, 2020 12:43 pm
- Forum: 8-bit acorn hardware
- Topic: Faulty Master???
- Replies: 20
- Views: 910
- Sun Oct 18, 2020 11:52 am
- Forum: 8-bit acorn hardware
- Topic: Faulty Master???
- Replies: 20
- Views: 910
- Sat Oct 17, 2020 9:57 pm
- Forum: 8-bit acorn hardware
- Topic: Faulty Master???
- Replies: 20
- Views: 910
Re: Faulty Master???
Did anyone try to run the AMX disc image on a master? The CTRL-Break behaviour is as you describe on my Master. I've known the "Bad sum" error happen when ROM code is loaded into sideways RAM and the initialising code tries and fails to grab memory for itself. In such cases one workaround...
- Sat May 23, 2020 7:05 pm
- Forum: introduce yourself
- Topic: Hello from Holmfirth!
- Replies: 9
- Views: 755
Re: Hello from Holmfirth!
Good luck. You're from a lovely area, though you won't need telling. I used to have an aged relative who lived opposite Park Head Fisheries and took the opportunity to combine visits with walks around the area (Diggle dam etc). I even have a couple of Ashley Jackson paintings from that (pre-LOTSW) p...
- Sun Apr 12, 2020 10:46 am
- Forum: 8-bit acorn hardware
- Topic: Slow Speech from TMS6100 Emulator
- Replies: 9
- Views: 769
Re: Slow Speech from TMS6100 Emulator
The instructions do, however, say that "this is a simple matter of adjusting VR2". As you'll find out it's not quite that simple as one of the upgrade ICs is in the way. Still, it's much easier that with earlier issue boards than yours where the value of R32 needs to be adjusted. I made th...
- Mon Apr 06, 2020 7:50 pm
- Forum: general
- Topic: Today I received.....
- Replies: 6133
- Views: 701010
Re: Today I received.....
Received, as a gift, a nice little Z84 single board computer. Lots of bank-switching flexibility and even the possibility to run CP/M from a CF card. http://linc.no/products/linc80-sbc Also got with it a digital IO card, ROM card, busboard (backplane) and Z50Bus prototype card. It'll make a nice sib...
- Tue Mar 31, 2020 2:54 pm
- Forum: general
- Topic: Master spray job
- Replies: 36
- Views: 4056
Re: Master spray job
Aye, I was careful to say in my post that I'd used the Brillo Bone formulation. After 18 months I've become thoroughly used to the colour and am very happy with it. It looks, to my adjusted synaptic pathways, close enough to a virgin machine, though it's obvious that there is a difference from it im...
- Wed Mar 25, 2020 7:30 am
- Forum: general
- Topic: Master spray job
- Replies: 36
- Views: 4056
Re: Master spray job
I haven't tried Champagne. I was quite likely put off because that just happens to be the colour of the bathroom suite! I also made a mistake above when I mentioned that "ivory" looked too dark. That should have been "Natural" is too dark. I've corrected that.
Alan
Alan
- Fri Jan 17, 2020 10:06 am
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
Re: WE EPROM Programmer. ROM images etc
I noticed that none of the version 4 images work with the Master 128. This is due to the ROM header specification combined with a subsequent osbyte 8E call. I've modified the version 4 image to correct the problem. This image should now work on both M128s and Bs: EP104M.ROM This is based on the file...
- Tue Dec 17, 2019 8:10 pm
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Masters of the Universe - Super Adventure: Another one with SAVE/LOAD problems under 'Play'. It appears happy with the SAVE GAME command but doesn't produce a file on disc after choosing a numerical slot. It works OK from download.
Alan
Alan
- Sun Dec 15, 2019 10:15 am
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
Re: WE EPROM Programmer. ROM images etc
The EPROM programmer is now working. It took longer than expected to fix as a UK supplier sent me some bad 8255 ICs. You also have to be very careful with suppliers of 2564 EPROMS. A heuristic seems to be that if the ICs don't have a raised platform around the window then they're probably not 2564s....
- Thu Dec 12, 2019 6:43 pm
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Lords of Time (both versions using 'Play'). These suffer from the usual kinds of SAVE/RESTORE failures owing to WP/ACCESS settings.
Alan
Alan
- Mon Dec 09, 2019 6:21 pm
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Something to bear in mind when testing games via the Play button on bbcmicro.co.uk is that you can switch to the experimental (and still slightly broken) installation of a more up-to-date version of JSBeeb by changing the text "jsbeeb" in the URL to "jsbeebng". Useful info thank...
- Sun Dec 08, 2019 5:08 pm
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
The version of Contraption on bbcmicro will certainly not work on a Master. Amongst other things it messes about with the system row multiplication code.
The attached version should work, though I haven't played it through. IIRC it's a version that has previously been posted to stardot.
Alan
The attached version should work, though I haven't played it through. IIRC it's a version that has previously been posted to stardot.
Alan
- Sun Dec 08, 2019 11:58 am
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Hi Mick,
Splendid. The ideal solution. Thanks.
Alan
Splendid. The ideal solution. Thanks.
Alan
- Sun Dec 08, 2019 11:09 am
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Thanks Lee & Mick, Mea culpa. I had the sound off - it seemed a shame to disturb the hound while she's happily snoring away. I suppose a pedant might say that the prompt should disappear once a key is pressed but that would seem like stupidly trying to justify my error. I'll take your word about...
- Sun Dec 08, 2019 7:25 am
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Leapfrog (IJK): After a nice long patch of not finding any problems I find two titles in a row. This one isn't severe though. When run the program displays "PART ONE HAS NOW LOADED PRESS ANY KEY". At that point it is very unresponsive to key presses except, unusually for a commercial title...
- Sun Dec 08, 2019 6:59 am
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
Lazer Cycle is showing a couple of things that appear wrong. First, there seems to be no way of skipping the painfully slow-scrolling intro text (pressing Escape just starts the scrolling from the beginning). Secondly, the main game seems to be particularly unresponsive to key presses, though I coul...
- Thu Nov 28, 2019 6:16 am
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
Re: WE EPROM Programmer. ROM images etc
They were all LS types. The 7400 still is, the 74138s are currently HCT types. Thanks for the floating info; I did refer back to 74 series data sheets yesterday and didn't chance upon any that said what happened to voltage levels of unused gates. From what you say, following best practice may defini...
- Wed Nov 27, 2019 9:24 pm
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
Re: WE EPROM Programmer. ROM images etc
Here's a just-completed schematic for the programmer. Please let me know if something looks wrong. WE-Eprom-Programmer.pdf It should be a help in sorting it out and vital for working out the correct FCxx addresses to use. It was not possible to extract the 8255 without damage to the socket. Having r...
- Mon Nov 25, 2019 8:57 pm
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
Re: WE EPROM Programmer. ROM images etc
Thanks, but the design of the WE programmer is such that an internal 8255 is programmed by the ROM software to route the pins properly.
Alan
Alan
- Mon Nov 25, 2019 7:50 pm
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
Re: WE EPROM Programmer. ROM images etc
Thanks Dave. For completeness there is this v4 posted elsewhere in this forum: 8ccf49a17e39f2d9ce22c03afbf99147 "EPROM V4 Mark David (C) MDM Software 1984" WTFEPRM.ROM The ROMS on http://archive.retro-kit.co.uk/bbc.nvg.org/rom/Watford/util/index.html are covered in your zip (as v4 and v8)....
- Mon Nov 25, 2019 10:17 am
- Forum: introduce yourself
- Topic: Hi, from Katikati New Zealand!
- Replies: 13
- Views: 1342
Re: Hi, from Katikati New Zealand!
Please pass on our regards to The 3rd Disgusting Fusiliers.
Coincidentally some of your kit is in the post to me. Good to see you on here.
Alan
Coincidentally some of your kit is in the post to me. Good to see you on here.
Alan
- Mon Nov 25, 2019 9:57 am
- Forum: 8-bit acorn hardware
- Topic: WE EPROM Programmer. ROM images etc
- Replies: 16
- Views: 1655
WE EPROM Programmer. ROM images etc
I recently acquired a Watford Electronics Eprom programmer from eBay. It's not an Adder and doesn't say 'Mk II' on the case (though it does look like one). I assume it may be a 'Mk I'. It was in a bit of a state. Ultra-thin mains cable, blown chassis fuse, shorted bridge rectifier, the leads of some...
- Sat Nov 16, 2019 9:40 am
- Forum: 8-bit acorn hardware
- Topic: EPROM?
- Replies: 8
- Views: 1264
Re: EPROM?
I'm assuming you mean the "TL866 II plus", in which case the command line tool 'minipro' appears to work under Fedora Linux after doing a "dnf install minipro" dmesg then shows: [ 6406.745914] usb 1-13: new full-speed USB device number 11 using xhci_hcd [ 6406.874020] usb 1-13: N...
- Wed Nov 13, 2019 9:43 am
- Forum: the complete BBC games archive
- Topic: Games with problems
- Replies: 93
- Views: 11353
Re: Games with problems
"Johnny" is showing some minor consequences of tape to disc conversion. First, the instruction screen disappears too quickly. Secondly the 'SAVE' command gives the option of "Tape or Memory" whereas disc is the permanent storage medium used. Thirdly, the save to disc bombs out ow...