A1200 motherboard revisions

[Tenacious]

My current A1200 motherboard has a blown parallel port and PCMCIA (given to me that way).  I think that I'm about to order a new or refurbished A1200 motherboard from AmigaKit.  I understand that there are mb revisions that should be avoided, but don't know which ones.

Appearently, there are also different clockport configurations.  I intend to connect a Delfina Flipper to this (already have it).

I have already gathered the following upgrades/accessories.

ScanMagic/FlickerMagic
4xEIDE and EIDE'99 software
Lyra 1200  (may not use)

I will be looking for an 030 accelerator that takes 128MB of ram.

I would appreciate the sage advice of those who have been down this road already.

[AmiBoy]

As far as I can remember Rev 1d.4 and 2.B can have problems with timing issues but these are only really supposed to manifest temselves with faster processors (040 or 060) and if you expand you 1200 too much (i.e. graphics card, faster IDE etc).

I think you should be ok with the expansions you are going to be using.

Also some floppy disk drives that came with Escom A1200's (these were mostly revision 2.B motherboards) had something wrong with them (as they were cheap converted PC floppy drives) that caused some older Amiga games to not be recognised by the system and hence unplayable.

[DrValkyer]

It's true that some mobo revisions have timing problems but for example I got a 1D.4 mobo with Blizzard-040/PPC accelerator and everything works perfectly.

Could it be possible that all 1D.4 revision mobos are not identical?

[JaXanim]

Just dug out my old Eyeline Direct newsletters if anyone still remembers those. The May 1999 issue gave us chapter and verse on the mobo timing issues and what Commodore and their ilk did and didn't do about them. Here's an overview.

The main UK selling board was the 1.D.1 and this was pretty well fixed during manufacture. A few early, pre-main-production revisions, notably 1.A and 1.B were also sold and these also had timing workarounds fitted.
Commodore planned to correct the Budgie and Gayle faults and went ahead with revisions 1.D.4 and 2.B which didn't have provision for the fixes. They planned to fit updated chips, but by then, the company was sinking and these boards went on sale with no fix available. So,fitting fast accelerators, fast IDE controllers and clock port accessories to these may cause timing issues. Similar boards were manufactured by Amiga Technologies/Escom starting in 1995, but early sales (15-20% of those sold) didn't get fixed either.

Many of these boards were fixed by Eyetech to bring 1.D.4 and 2.B boards up to the original 1.D.1 standard, but some of them have 'insoluble' issues. These are found when using a Zorro 3 bus which requires the Budgie revision - and never happened.

Many people run 1.D.4 boards without issues. My old tower has one and has lots of heavy stuff on it. There's an '060, a Power Flyer, a Catweasel, Silver Surfer, etc. The only problem I had was when trying to run both a PicassoIV and a VooDoo5 together on the Elbox Z4 bus. Elbox confirmed it was timing problems after a lengthy diagnostic session by email. Other than that my 1.D.4's been faultless.

JaX

[RW222]

There was some issues with the modulator in early boards, don't know the revision offhand, only that mine has the problem. I think there's a fix on aminet. I was never thrilled with the picture on a TV before the modulator went screwy so haven't bothered to fix mine, since I was first using it with an RGB Monitor/TV then a 1084S. Might have been a PAL only issue, not sure.

Edit: actually I'd have thunk if those guys know their stuff, they'd have checked for the issue and patched it if present, if it was gonna go, it woulda went by now.

[Tenacious]

Thanks guys!  The purpose of this machine is to get maximum compatibility and AGA graphics (I already have graphic cards on other machines).

Any recommendations on specific accelerator cards that allow 128 Megs of fast ram?  68030 is plenty of power for me.

[rkauer]

 Various, but I use a Microbotics A1230 XA. With a single 128Mb SIMM in it.

 You can use a Blizzard, with the SCSI kit you'll can use 256Mb at one time.

[rockape]

Hi,

Theres some good info on

http://www.ianstedman.co.uk/Amiga/amiga_hacks/A1200_Mobo_fix/a1200_mobo_fix.html

Kind Regards, Michael

aka rockape

[BinoX]

The Blizzard acclerator cards got around the problem by having buffered access to the A1200 motherboard, whereas the apollos had no such buffering...

As a consequence the Blizzard's access to anything on the motherboard (chip ram, custom chips, powerflyers etc) was slower than the Apollo's, however it did mean that the Blizzard's would run stable in machines with timing issues.

The Apollos however were technically faster, although could be unstable or just not work on unfixed boards...
I've never personally owned an Apollo card so I don't know the real difference in speed... But my boss/friend/Frank said the apollo transfer speeds were much faster when used in conjunction with a powerflyer.

[Hodgkinson]

I've just had a look on the AmigaKit site out of interest and they don’t seem to specify the motherboard revisions that they sell (Or i've just missed it).

Anyone know what might be a reasonable price these days for a 128MB 72Pin EDO SIMM @ 60nS ? I've seen some for ~£25, but I don't know if they are still sold or what nS they are.
I’m thinking about maxing out the RAM on a Blizzard 1230IV for the sake of it - Having said that I only use a quarter of the 64MB that is in at the moment and that’s assigned to DOS Emulation.

Thanks for raising the issue about mobo revisions, folks! I was going to ask about the same thing...

Hodgkinson.

[Gavilan]

Even tough what @Amiboy says is true, i can tell about my personal experience.
I have never ever seen a different mobo revision other than 1D4 in this part of the world (Argentina)

I have seen about 60/70 Amiga 1200 and belive me, ALL were 1D4.

My own Amigas (i have 4 A1200) have been tested succesfully with either a 040/060 and/or PPC cards & BVision cards
I never in my life suffered those timing issues problems

Maybe i was lucky and my mobos were already fixed?
IS there a way to know if the time fixing was made?
I can take some pics of the mobos and post them here if that helps

Cheers
Sebastian

[Hodgkinson]

The only C= alteration to the boards is a resistor at the front of the board soldered on top of some unused SMD pads (I think its between the ROM's and the custom chips...).

Hodgkinson.

[AmigaMance]

Maybe i was lucky and my mobos were already fixed?

 Most likely!

IS there a way to know if the time fixing was made?

 If you expose the mobo you should see some wire or resistor(s) soldered, like Hodgkinson said.

[Damion]

BinoX wrote:
The Blizzard acclerator cards got around the problem by having buffered access to the A1200 motherboard, whereas the apollos had no such buffering...

As a consequence the Blizzard's access to anything on the motherboard (chip ram, custom chips, powerflyers etc) was slower than the Apollo's, however it did mean that the Blizzard's would run stable in machines with timing issues.

The Apollos however were technically faster, although could be unstable or just not work on unfixed boards...
I've never personally owned an Apollo card so I don't know the real difference in speed... But my boss/friend/Frank said the apollo transfer speeds were much faster when used in conjunction with a powerflyer.

Interesting info there. I'll shortly be acquiring an Apollo 1260, and it will be fun to compare benchmarks I still have saved from my old Blizzard 1260. (Also, I'm curious to see if the Apollo is as rock solid on my 1D4 mobo as the Blizz was.)

I had an IDE-Fix "Express" at the time, and it made little (if any) speed improvement with the Blizzard. Seems I should better luck with the Apollo.

 

[Tenacious]

I recently read a disturbing thread from Amiga4001.  It seemed he had trouble with Delphina sound cards working in A1200s.  I had trouble understanding the specifics and haven't heard back from him.

So, does anyone have a Delfina, especially a Flipper version, working in a 1200?