VIDC Enhancer

[Mike Howard]

Hi All,

My apologies if this is old hat or been done to death but I've been away
from the Acorn/RiscOS scene for a number of years now.

I'm firing up some old Acorns (just for the halibut!) and would like to fit
VIDC Enhancers to a couple of A3000s. I'm not adverse to buying them (if
only they were for sale anywhere), alternatively I thought I'd build them.

I got hold of Andreas Barth's autoVIDC Enhancer project info but as I'm no
electronics guru it's not palin sailing. In fact I'm finding it really
difficult to find a couple of the components. One is the IC, 74ALS00, and
the other is the 36MHz TTL Oscillator. I know nothing of either of these
components and trawling the net comes up with a few references to the
74ALS00 but often with suffixes like AN or AS. As for the oscillator, (this
may be a silly question) is this Acorn specific? I can find higher and lower
frequency oscillators but not at 36MHz.

If anybody has any help or info on the subject I'd be grateful. Or if anyone
knows of any lying around (I did have one myself but when you need
something.......)

Regards,
Mike.

[Ian Molton]

On Tue, 08 Jul 2003 01:05:49 +0100
Gary Locock <gary@locock.demon.co.uk> wrote:
Only one question... is it worth it?

Depends if its fun :)

Theres always the colourcard.

please, dont be so quick to damn the old machines - they are still very useful. I use !Draw on my A410 regularly. Yes, an A7k does it quicker, but the A410 does it Quick Enough (tm)

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

[Mike Howard]

Hi,

It's worth it to me. As I said in my OP, it's just for the halibut! I do
have other Acorm machines, including RiscPC & A7000 (plus Acorn
Electron, BBC Master ....).

Just something I want to do is all! :)

Cheers,
Mike.
--
Gary Locock wrote: In article <becsan$2ot$1@titan.btinternet.com>, Mike Howard <aixguru@btopenworld.com> wrote:Hi All,My apologies if this is old hat or been done to death but I've been awayfrom the Acorn/RiscOS scene for a number of years now.I'm firing up some old Acorns (just for the halibut!) and would like to fitVIDC Enhancers to a couple of A3000s. I'm not adverse to buying them (ifonly they were for sale anywhere), alternatively I thought I'd build them.I got hold of Andreas Barth's autoVIDC Enhancer project info but as I'm noelectronics guru it's not palin sailing. In fact I'm finding it reallydifficult to find a couple of the components. One is the IC, 74ALS00, andthe other is the 36MHz TTL Oscillator. I know nothing of either of thesecomponents and trawling the net comes up with a few references to the74ALS00 but often with suffixes like AN or AS. As for the oscillator, (thismay be a silly question) is this Acorn specific? I can find higher and lowerfrequency oscillators but not at 36MHz. Only one question... is it worth it? By the time you spent all this time and effort, you've still only got an A3000 with slightly better graphics... which might or might not work. You could buy an A7000 or A7000K for not a lot of money, and you would have a /much/ more capable computer. In fact even an A3010/A3020 is a better bet, and those are being given away. A700K /or/ A30x0, take up a lot less desk space too...

[Theo Markettos]

Mike Howard <aixguru@btopenworld.com> wrote: Hi All, I got hold of Andreas Barth's autoVIDC Enhancer project info but as I'm no electronics guru it's not palin sailing. In fact I'm finding it really difficult to find a couple of the components. One is the IC, 74ALS00, and the other is the 36MHz TTL Oscillator. I know nothing of either of these components and trawling the net comes up with a few references to the 74ALS00 but often with suffixes like AN or AS. As for the oscillator, (this may be a silly question) is this Acorn specific? I can find higher and lower frequency oscillators but not at 36MHz.

Any 74ALS00 should be OK - the suffix only says what type of package it's in
(small or ant-scale). Different manufacturers have different letters for
their packages, but a 74ALS00N or AN will probably be a DIL or DIP package
which is what you want. If you can't find one, a 74F00 or 74ACT00 (in
DIL/DIP) should do the same job.

The oscillator isn't Acorn specific, but you do need that frequency which
seems to be rather rare. http://www.cmac.com/mt/ were very nice when I
wanted a crystal that only they stocked - so it might be worth asking them.

Theo

--
Theo Markettos theo@markettos.org.uk
Larisa, Greece theom@chiark.greenend.org.uk
http://www.markettos.org.uk/

[Steffen Huber]

Mike Howard wrote:
[snip] As for the oscillator, (this may be a silly question) is this Acorn specific?

No. Every old electronic parts dealer in Germany seems to have them, for
around 2 EUR per piece.
I can find higher and lower frequency oscillators but not at 36MHz.

Strange.
If anybody has any help or info on the subject I'd be grateful. Or if anyone knows of any lying around (I did have one myself but when you need something.......)

I might have some somewhere, but I could also buy a few and send them to
you.

And while you're doing fany upgrades for your A3000, and they are ARM2
models, I recommend to also do the TurboA3000 upgrade - this speeds
up the memory access (it ups the bus frequency to 12/13,3/16 MHz
depending on the oscillator frequency you use), given that your RAM
and ROM is fast enough. 70ns RAMs usually work with at least 13,3 MHz.

The TurboA3000 upgrade needs desoldering of an IC, however. But
if you want to enjoy using Mode 31 with your VIDC Enhancer, it is highly
recommended.

It might also be a bit complicated to fit both upgrades at once - I once
designed a PCB which contains both the Turbo upgrade and the VIDC Enhancer,
but it somehow got lost. Not hard to do it yourself, though.

Steffen

--
steffen.huber@gmx.de steffen@huber-net.de
GCC for RISC OS - http://www.arcsite.de/hp/gcc/
Private homepage - http://www.huber-net.de/

[Mike Howard]

Steffen Huber wrote:[snip]As for the oscillator, (thismay be a silly question) is this Acorn specific? No. Every old electronic parts dealer in Germany seems to have them, for around 2 EUR per piece.

Thanks. With advice from Andreas Barth I did find the 36MHz oscillator
at the Conrad(Deutchland) website, at a cost of 5.09 Eur each. Their
minimun order is 50 Eur though. I have not been able to find a single UK
supplier.

[snip] I might have some somewhere, but I could also buy a few and send them to you.

Either way, I would be very grateful and obviously reinburse you.
And while you're doing fany upgrades for your A3000, and they are ARM2 models, I recommend to also do the TurboA3000 upgrade - this speeds up the memory access (it ups the bus frequency to 12/13,3/16 MHz depending on the oscillator frequency you use), given that your RAM and ROM is fast enough. 70ns RAMs usually work with at least 13,3 MHz. The TurboA3000 upgrade needs desoldering of an IC, however. But if you want to enjoy using Mode 31 with your VIDC Enhancer, it is highly recommended.

Thanks for the advice, I'll look for deatils of the TurboA3000 upgrade
on the web.

Thanks for your help Steffen.

Mike.
--

[Ian Molton]

On Thu, 10 Jul 2003 20:32:09 +0000 (UTC)
Mike Howard <aixguru@btopenworld.com> wrote:
I might have some somewhere, but I could also buy a few and send them to you. Either way, I would be very grateful and obviously reinburse you.

I could use two please.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

[Gary Locock]

In article <20030708010734.26a307cc.spyro@f2s.com>,
Ian Molton <spyro@f2s.com> wrote: On Tue, 08 Jul 2003 01:05:49 +0100 Gary Locock <gary@locock.demon.co.uk> wrote:
Only one question... is it worth it?
Depends if its fun :)
Theres always the colourcard.

Which uses up the only podule slot IIRC, and isn't needed at all on later
machines to get above 256 colours.
please, dont be so quick to damn the old machines - they are still very useful.

I don't damn them at all, I just asked a question. ISTM though that it might
involve less effort to get a newer better machine for next to nothing at
current values. Worth thinking about at least.
I use !Draw on my A410 regularly. Yes, an A7k does it quicker, but the A410 does it Quick Enough (tm)

Fair enough.

--
Gary Locock, Network Manager, Bablake Junior School
Coundon Road, Coventry CV1 4AU
School Website: http://www.bablakejs.co.uk

[Ian Molton]

On Fri, 11 Jul 2003 00:04:50 +0100
Gary Locock <gary@locock.demon.co.uk> wrote:
I don't damn them at all, I just asked a question. ISTM though that it might involve less effort to get a newer better machine for next to nothing at current values. Worth thinking about at least.

I just hate seeing A4xx / 5xx machines going for scrap I guess ;-)

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.