Search found 47 matches

by philb
Mon Sep 18, 2017 7:59 pm
Forum: hardware
Topic: Resurrecting A5000
Replies: 41
Views: 1040

Re: Resurrecting A5000

the battery is well clear of the other circuitry It's a bit hard to see from the photo you linked to, but unless your MDFS has a significantly different PCB layout to mine the battery is actually quite close to some of the other parts including the R/C network that controls the timing of the DRAM a...
by philb
Sat Sep 16, 2017 9:11 am
Forum: upcoming and recent events & exhibitions
Topic: Retro Computer Festival - CCH, Cambridge - 16 & 17 September 2017
Replies: 28
Views: 1017

Re: Retro Computer Festival - CCH, Cambridge - 16 & 17 September 2017

Sounds good. Sadly my wife has other plans for this weekend but I will see if I can get over there tomorrow for an hour or so!
by philb
Fri Sep 15, 2017 7:08 pm
Forum: hardware
Topic: Acorn 3000 4mb Ram Expansion
Replies: 30
Views: 511

Re: Acorn 3000 4mb Ram Expansion

My A3000 currently has a 2mb ram module in it. The machine posts as 2mb so not sure if there is on onboard ram in addition to the module or not :shock: Yes, there is 1MB on the baseboard and another 1MB on the expansion card. I can't find anything on Ebay. Does anyone know if it would be easy / pos...
by philb
Wed Sep 13, 2017 8:56 pm
Forum: hardware
Topic: DCI-4 Econet driver
Replies: 7
Views: 388

Re: DCI-4 Econet driver

Oh, that's interesting. I just recently started work on a version 2 of my old Econet/AUN gateway board. Maybe we should pool our resources. I was about to say that the source code for version 1 was on github, but it turns out that this is not the case: it was on berlios.de but that site is defunct. ...
by philb
Tue Sep 12, 2017 9:20 pm
Forum: hardware
Topic: Dead MDFS Resurrection
Replies: 192
Views: 7829

Re: Dead MDFS Resurrection

Ottly wrote:I wonder if maybe the same board was used for the HDFS or whether they are for clock circuitry? No idea though.


No, the HDFS was a significantly different (and rather larger) board. It had two Z80 CPUs among other things.
by philb
Tue Sep 12, 2017 9:13 pm
Forum: hardware
Topic: Broken MDFS
Replies: 5
Views: 285

Re: Broken MDFS

C3 turned out to have completely disintegrated. It looks like this is involved in controlling the RAS/CAS mux so that might be bad news. I have replaced it with a 480pF cap that I had lying around but still no joy. After further reading of the aforementioned long thread, I discovered that C3 is mea...
by philb
Tue Sep 12, 2017 8:19 pm
Forum: hardware
Topic: Some question about my A3010. Adelaide & IDEtoCF
Replies: 18
Views: 440

Re: Some question about my A3010. Adelaide & IDEtoCF

But be careful because some DOMs have the same issues as CF and SD, with compatibility problems on the RISC OS 3.1 Acorn and Castle IDE interface. Does anybody know what it is that ADFS is doing to cause these compatibility problems? Is there some command it expects to use that newer IDE devices do...
by philb
Mon Sep 11, 2017 9:42 pm
Forum: hardware
Topic: Troubleshooting my latest BBC B
Replies: 70
Views: 895

Re: Troubleshooting my latest BBC B

If Ctrl-Break and power-on both make it fail, but regular Break works, that sounds as though the machine is correctly identifying the type of reset but that some operation in the startup code (which is performed for a cold boot and skipped for a warm boot) is making it go wrong. But, that said, I ca...
by philb
Mon Sep 11, 2017 9:19 pm
Forum: hardware
Topic: Troubleshooting my latest BBC B
Replies: 70
Views: 895

Re: Troubleshooting my latest BBC B

When you say "hard reset", do you mean that Ctrl-Break also puts it into the broken state (but Break on its own works as expected)?
by philb
Mon Sep 11, 2017 11:32 am
Forum: hardware
Topic: Acorn A3000 Address exception on boot
Replies: 12
Views: 276

Re: Acorn A3000 Address exception on boot

Yes I can solder. I've heard on this forum of people getting these to work with BenQ monitors, do Acorn output to VGA cables exist? Yes, I think the Welcome Guide has details of the pinout, or it's certainly on the web. I'm not sure if you can buy them off the shelf anywhere anymore. Note though th...
by philb
Sun Sep 10, 2017 8:30 pm
Forum: archive submissions
Topic: Fileserver software
Replies: 4
Views: 145

Re: Fileserver software

danielj wrote:the level 2 discs seem to be on 8BS? http://www.8bs.com/econet.htm


Ah yes, right. Looks like only the utilities though, not the master disk, unless I'm reading that wrong.

I'll see if I can figure out a way to image the SJ ones.
by philb
Sun Sep 10, 2017 7:50 pm
Forum: archive submissions
Topic: Fileserver software
Replies: 4
Views: 145

Fileserver software

Found the following disks, does anybody know if they are already archived somewhere? I would have assumed so but couldn't find them with a few minutes of googling.

Level 2 file server master disk
Level 2 file server utilities disk
SJ FDFS 0.92 master disk
SJ Modem Server 02feb89
by philb
Sun Sep 10, 2017 6:56 pm
Forum: software: other
Topic: TCP/IP for Econet
Replies: 3
Views: 174

Re: TCP/IP for Econet

Oh, so you did. Good job there.

I have no doubt there are at least a couple of bugs in it. :D I should get it running again myself and see if I encounter any of those issues.
by philb
Sun Sep 10, 2017 6:24 pm
Forum: software: other
Topic: Slow OSBGET file access
Replies: 8
Views: 230

Re: Slow OSBGET file access

I guess DFS must be able to buffer a whole sector somewhere otherwise OSBPUT (or any write of less than a whole sector) couldn't work. And clearly if OSBGET was going to the disk every time then the throughput would be terrible, one byte per rotation of the disk which would be something like 5 bytes...
by philb
Sun Sep 10, 2017 1:16 pm
Forum: software: other
Topic: Slow OSBGET file access
Replies: 8
Views: 230

Re: Slow OSBGET file access

The overhead of OSBGET certainly can be significant, though how significant depends on the filesystem. On NFS (not ANFS or ENFS) the throughput for unbuffered byte-at-a-time access can easily be down in single digits. There are a variety of utilities around which will intercept OSBGET/OSBPUT and con...
by philb
Sun Sep 10, 2017 8:38 am
Forum: for sale / freebies
Topic: FTGH: A3000 user port/MIDI podule
Replies: 0
Views: 49

FTGH: A3000 user port/MIDI podule

I unearthed one of these in my study. I'm not entirely sure whether it works or not, but the circuit is sufficiently simple that there can't be very much wrong with it :D

Any use to anybody here? If so, PM me your address and you can have it.
by philb
Sun Sep 10, 2017 8:11 am
Forum: software: other
Topic: TCP/IP for Econet
Replies: 3
Views: 174

TCP/IP for Econet

Continuing my trawl through old disks, I uncovered the source code to an implementation of TCP/IP that I wrote for the BBC in about 1995. It speaks the same wire protocol as EconetA. In case anybody is interested I have put the source on github:

https://github.com/philb/bbc-iprom
by philb
Sat Sep 09, 2017 8:24 pm
Forum: archive requests
Topic: ABC 310 80286 Co-Pro ROMs
Replies: 10
Views: 437

Re: ABC 310 80286 Co-Pro ROMs

Do we have the ROMs from the 80286 co-pro anywhere? I'd imagine them to be very similar to those from the 80186 but would at least expect a different startup banner that doesn't mention 80186. Did you already find a copy of these? If not, I unearthed my 80286 board the other day and I have just exh...
by philb
Fri Sep 08, 2017 8:20 pm
Forum: hardware
Topic: DCI-4 Econet driver
Replies: 7
Views: 388

Re: DCI-4 Econet driver

Having exhumed the source to the DCI3 version I thought I might as well put it on github: https://github.com/philb/econeta If anybody wants to convert it to DCI4 then of course they're welcome to do so. Also the source for my Econet packet monitor that I found at the same time: https://github.com/ph...
by philb
Thu Sep 07, 2017 11:44 am
Forum: hardware
Topic: Acorn A3000 Address exception on boot
Replies: 12
Views: 276

Re: Acorn A3000 Address exception on boot

The reason for using vinegar is to neutralise any alkaline residue from the battery leakage. IPA won't do that. You could probably use IPA as a final rinse to get rid of the vinegar, but clean water will work just as well and might actually do a better job at removing some of the contamination. I wo...
by philb
Thu Sep 07, 2017 11:25 am
Forum: hardware
Topic: Acorn A3000 Address exception on boot
Replies: 12
Views: 276

Re: Acorn A3000 Address exception on boot

That looks like RISC OS 3. I think the RISC OS 2 ROMs didn't occupy the full width of the sockets. The reason I asked is that RISC OS 3 has a more extensive POST and if it gets as far as showing you a prompt then I guess the POST must not be detecting any errors. The MIDI card is unlikely to be a pr...
by philb
Thu Sep 07, 2017 9:37 am
Forum: hardware
Topic: Unpicking and re-creating Etherlan 550 ROM
Replies: 45
Views: 680

Re: Unpicking and re-creating Etherlan 550 ROM

danielj wrote:Phil, I'm going to send the others back to you, so up to you what I put in the ROM on those? From my perspective I'm fine leaving out net and bootnet as I'm never going to be booting off a fileserver.


Sure, sounds good.
by philb
Thu Sep 07, 2017 9:36 am
Forum: hardware
Topic: Unpicking and re-creating Etherlan 550 ROM
Replies: 45
Views: 680

Re: Unpicking and re-creating Etherlan 550 ROM

The difficulty with including decompression in the loader is that the loader entry point only returns one byte at a time to RISC OS (because of the small addressing window through to the podule, and that initial load time was not seen as critical). So the loader is called repeatedly, to extract eac...
by philb
Thu Sep 07, 2017 6:37 am
Forum: hardware
Topic: Acorn A3000 Address exception on boot
Replies: 12
Views: 276

Re: Acorn A3000 Address exception on boot

"Address exception" means that the software tried to access a nonexistent memory address. Registers on the ARM2 are 32 bits wide but the address space is only 26 bits. Any attempt to use a value with one of the high 6 bits set as an address will cause an address exception. In your case the...
by philb
Thu Sep 07, 2017 6:26 am
Forum: hardware
Topic: Unpicking and re-creating Etherlan 550 ROM
Replies: 45
Views: 680

Re: Unpicking and re-creating Etherlan 550 ROM

I suppose if you didn't care about RISC OS 2 compatibility at all then you could store the modules compressed in the ROM and have the loader run them through Squash_Decompress. It'd be a bit slow, but I think the OS only loads them once.
by philb
Wed Sep 06, 2017 2:21 pm
Forum: hardware
Topic: Broken MDFS
Replies: 5
Views: 285

Re: Broken MDFS

Replaced the battery. It wasn't obviously leaking but some of the surrounding components were a bit fuzzy so I gave it a cleanup with some vinegar and a wash. C3 turned out to have completely disintegrated. It looks like this is involved in controlling the RAS/CAS mux so that might be bad news. I ha...
by philb
Wed Sep 06, 2017 12:56 pm
Forum: hardware
Topic: DCI-4 Econet driver
Replies: 7
Views: 388

Re: DCI-4 Econet driver

I found the source code for the one I wrote in 1993 but this turns out to have been for DCI3. However, I also uncovered a binary copy of a DCI4 driver dated 1998 and apparently written by Acorn and DesignIT. I can make either of both of those available if they are any use.
by philb
Tue Sep 05, 2017 8:07 pm
Forum: hardware
Topic: Unpicking and re-creating Etherlan 550 ROM
Replies: 45
Views: 680

Re: Unpicking and re-creating Etherlan 550 ROM

http://mdfs.net/Apps/Networking/ARMLib.zip seems to have an "RMSave" utility which I assume does the opposite of RMLoad.

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