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by SarahWalker
Thu Sep 17, 2020 12:52 pm
Forum: 32-bit acorn hardware
Topic: A5000 repairs
Replies: 56
Views: 755

Re: A5000 repairs

I wonder if there's some special magic on the A4 (something else on the I2C bus maybe?) Battery Management Unit is also present on the I2C bus on the A4. Technically it shouldn't be affecting accesses to the (absent) CMOS RAM chip... On the four machines I've seen CMOS RAM chip failure on (2 A3000s...
by SarahWalker
Wed Sep 16, 2020 6:04 pm
Forum: 32-bit acorn hardware
Topic: A5000 repairs
Replies: 56
Views: 755

Re: A5000 repairs

Should emphasise that delete-power-on will not work if the CMOS RAM chip is faulty, as is quite likely.
by SarahWalker
Sun Sep 13, 2020 10:29 pm
Forum: 8-bit acorn software: classic games
Topic: Electron enhanced versions?
Replies: 13
Views: 897

Re: Electron enhanced versions?

Repton TLR takes advantage of sideways RAM to provide a full screen display. Probably more modern than you're asking for though. I have an Electron connected to a Plus 1 with an AP6 board installed (original PRES version). I have two static RAM chips installed. A GoSDC card makes use of one of thes...
by SarahWalker
Sat Sep 05, 2020 7:05 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

Yes, if you're willing to burn the space in cache. Edit: To be more specific : If you're not going to use the data again anytime soon, then yes, align to 8 words and try to read 8 words at a time if possible (as this will prevent the CPU being halted during the cache line fetch). If you _are_ likely...
by SarahWalker
Sat Sep 05, 2020 6:39 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

!SICK's memory results were annoying me enough for me to do some digging. It's using 12-word LDM/STMs for memory benchmarking, which provoke some suboptimal behaviour in ARM710 and (to a lesser degree) StrongARM, which have 8-word cache lines. For all the other CPUs (which have 4-word cache lines) i...
by SarahWalker
Sat Sep 05, 2020 2:38 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

Added in the O/C A3020 results, fleshed out the Mico a bit, also added !SICK main memory results (though IIRC !SICK applies a fudge factor so these shouldn't be taken as gospel).
by SarahWalker
Tue Sep 01, 2020 9:37 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

Yep, that's the correct border size. What's the performance in low detail mode? (press F5) You shouldn't need to modify any obey files, add '-timedemo demo1' in the 'Others' field under miscellaneous options. For the curious, Doom timedemo performance is (gametics / realtics) x 35. For the sake of f...
by SarahWalker
Mon Aug 31, 2020 8:01 am
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

Updated first post. I also tracked down a RISC OS 3 ARM2 w/MEMC1a Whetstone result to replace the blatantly rigged old-FPemulator-running-from-RAM A3000 result. Given that FPemulator would have been running from ROM it's not entirely surprising that ARM2 and ARM250 give basically the same result on ...
by SarahWalker
Mon Aug 31, 2020 7:34 am
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

My A3000 is running RISC OS 2 with an older FPemulator, so the FP results there probably aren't directly comparable with RISC OS 3 machines.

Cheers for the A420 results btw, interesting to see the relative impacts of CPU/memory speed. Just to check, this was in MODE 12?
by SarahWalker
Sun Aug 30, 2020 9:43 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

!SICK and CLOCKSP are readily available online, Doom+ can be got from your local dealer...

I've attached the Reach benchmarks. Both will run then print an execution time in centiseconds. Galaxy framerate is 436 / (centisecond execution time / 100), tunnel is 896 / (centisecond execution time / 100).
by SarahWalker
Sun Aug 30, 2020 5:38 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Re: Benchmarks

I'll give that a try, thanks.

In the mean time I've added numbers from a couple of scenes ripped from Reach. In the process of removing VRAM, my current RiscPC got its first taste of blood. I hate that case...
by SarahWalker
Sun Aug 30, 2020 3:47 pm
Forum: 32-bit acorn software: other
Topic: Benchmarks
Replies: 18
Views: 608

Benchmarks

I seem to have ended up going through a good variety of Arcs during lockdown... So I thought I'd benchmark them! I am aware I'm probably the only person who finds this interesting. Anyway, here are some results. See below for machine & benchmark details. If anyone can think of any other interesting ...
by SarahWalker
Sun Aug 30, 2020 11:22 am
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

I'm guessing it was not exactly a high volume product!

It's also interesting seeing the amount of unused space on the RAM card; I'm guessing they used the same PCB for 1-3 MB upgrades as well.
by SarahWalker
Sat Aug 29, 2020 2:50 pm
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

Will do when I next take the machine apart again...
by SarahWalker
Sat Aug 29, 2020 12:58 pm
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

Just been playing with the machine, with the exception of the missing battery the machine seems fully functional. It looks to be a bit of a mongrel; ALB55 implies a 210 MB hard drive, but there are two here, a 40 MB and 80 MB. The 80 MB throws regular disc errors unfortunately, but the contents look...
by SarahWalker
Sat Aug 29, 2020 12:24 pm
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

Well that was anticlimatic...

Jumper at LK2 was missing, which blocked the Kout signal to the keyboard. Fit that and DELETE power-on goes to the desktop.
by SarahWalker
Sat Aug 29, 2020 11:22 am
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

So this machine arrived yesterday. It's definitely an alpha - board is marked as '4M/33MHZ'. I opened it before turning it on, which is just as well as the MEMC board and CPU oscillator had come detached (is the latter normally socketed on an alpha?). When powered on it seems to run through the self...
by SarahWalker
Thu Aug 27, 2020 9:31 am
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

I'm sure I read somewhere that the FPA10 was mostly limited to 25 MHz, hence the main point of the FPA11 was to hit 33. Stepping back to this for a second, my FPA Upgrade Pack just arrived in the post. I find this note on the first page of the installation instructions to be interesting : The FPA m...
by SarahWalker
Tue Aug 25, 2020 1:16 pm
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

From the looks of that, a graphics card as well? Quite the beast of a machine.
by SarahWalker
Tue Aug 25, 2020 10:22 am
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

I'm sure I read somewhere that the FPA10 was mostly limited to 25 MHz, hence the main point of the FPA11 was to hit 33. There was also something about the A5000 PSU being too noisy for 33 MHz FPA to be reliable. Could of course be wrong though, it's not like I was paying attention to Acorn stuff at ...
by SarahWalker
Tue Aug 25, 2020 7:36 am
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

I was told some time ago by an ex-Acorn employee that the A540 33 MHz cards had hand-picked ARM3 and FPA10 chips that were known to work together...
by SarahWalker
Mon Aug 24, 2020 5:54 pm
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

IanJeffray wrote:
Mon Aug 24, 2020 5:45 pm
And put a cherry on the top: https://www.ebay.co.uk/itm//293704401471
MINE

Also it probably wouldn't work at 33 MHz anyway.
by SarahWalker
Sun Aug 23, 2020 9:10 pm
Forum: for sale / freebies
Topic: A5000 with Risc Developments Dual MEMC2
Replies: 32
Views: 1011

Re: A5000 with Risc Developments Dual MEMC2

I'd be interested in this.
by SarahWalker
Tue Aug 18, 2020 2:46 pm
Forum: 32-bit acorn hardware
Topic: Iyonix and PC Card
Replies: 1
Views: 158

Re: Iyonix and PC Card

No.
by SarahWalker
Thu Aug 13, 2020 10:23 pm
Forum: 32-bit acorn software: other
Topic: Bug in RISC OS Time/Date?
Replies: 7
Views: 397

Re: Bug in RISC OS Time/Date?

Possibly a daft question, but why are you loading !Killer at boot? Having it resident won't do anything, you only need the VProtect module loaded.

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