Broken Dragon

[Alastair]

I have a Dragon 32 with an issue 3 power board - (is there any way of checking which issue of the motherboard it is?)

You may wish to look at this site http://www.studio68.no/surveys/dragon/default.asp . If you click on the various links you will find information on how to identify the boards.

Many thanks Phill - there is a row of jumpers - they are all in the same position (closed from memory as the Dragon is not in front of me at the moment)

On my D32 issue 2 with OKI RAM the jumpers are set the same as the in the top photograph on this page http://www.studio68.no/surveys/dragon/ram.asp (and obviously so is Gareth's D32).

[RWAP]

Many thanks Phill - there is a row of jumpers - they are all in the same position (closed from memory as the Dragon is not in front of me at the moment)

On my D32 issue 2 with OKI RAM the jumpers are set the same as the in the top photograph on this page http://www.studio68.no/surveys/dragon/ram.asp (and obviously so is Gareth's D32).

Ah - mine has the piggy back setup - I will have to look see.

[prime]

If it helps people in the future I have uploaded some pictures of the various motherboards here :

http://archive.worldofdragon.org/index. ... d_Pictures

Phill.

[robcfg]

Nice pictures, Phill!

As soon as I get back home from holidays I'll try to do a 300dpi scan of my Dragon64 motherboard and upload it to the Motherboard Pictures page.

By the way, maybe we should order the pictures based on the model number because there can be a lot of revisions of the boards and that would make them easy to browse. Take a look here.

[prime]

Nice pictures, Phill!

As soon as I get back home from holidays I'll try to do a 300dpi scan of my Dragon64 motherboard and upload it to the Motherboard Pictures page.

I was going to do the 64's board tonight, I'll also do the Tano 64 and the Issue 1 Alpha at the same time.

By the way, maybe we should order the pictures based on the model number because there can be a lot of revisions of the boards and that would make them easy to browse. Take a look here.

Humm that might be a good idea, I guess a combination of MK number / Issue number would make the most sense cirtainly for the Dragon 32 boards, as I don't think (from memory) they have a specific part no on them.

Cheers,

Phill.

[robcfg]

I have a picture of my Dragon64's PCB here.

When I get back I'll do the 300dpi scans.

[admin]

There are 3 different types of Mark I Dragon 32 boards (All the MK 1 boards have the same layout with the exception of the RAM area:

• The original 16K board with 16K Piggy Back, labelled as (c) Dragon Data Services Ltd - Issue 2. Only circa 10,000 of these were produced before production moved to a 32K machine.
  The OKI board, labelled as (c) Dragon Data - Issue 2, using 8 OKI 16x16K RAM to give 32K.
  The Siemens board, labelled as (c) Dragon Data - Issue 2, using 16 Siemens 16x16K RAM to give 32K.

There are 2 types of Mark II board:
The Mark II Board, labelled as DRAGON DATA LTD CPU UK 32K MKII - Issue 5 or Issue 6 - with the SAM mounted horizontally to make room for 16 RAM chips on the main board.

There does not appear to have been an Issue 1,3 or 4 board put into production. The PSU board for the Dragon 32 comes in Issue 1,2,3 and 4. Issues 1 and 3 will be the most common and Issue 2 was withdrawn due to a modulator compatibility problem.

As for the Dragon 64, I used to think there was only 1 board but recently I have seen two different D64 boards.....

[prime]

I have a picture of my Dragon64's PCB here.

Humm that's odd you seem to have mask programmed roms on your 64 board, or at least OTP eproms, all the 64 boards I have seen up until now have had EPROMS in them.

Cheers.

Phill.

[prime]

There are 3 different types of Mark I Dragon 32 boards (All the MK 1 boards have the same layout with the exception of the RAM area:

• The original 16K board with 16K Piggy Back, labelled as (c) Dragon Data Services Ltd - Issue 2. Only circa 10,000 of these were produced before production moved to a 32K machine.

The ones that where supposedly origionally going to be 16K machines, until DD got wind of Sinclair releasing the 48K spectrum....

The OKI board, labelled as (c) Dragon Data - Issue 2, using 8 OKI 16x16K RAM to give 32K.

Those are the half good 4164 64Kx1 chips, the 48K spectrum also uses them for it's bank of 32K RAM, these boards are easy to upgrade to 64K by simply replacing the RAM chips with 4164s and doing the decoder mod, shame the OKIs where not socketed.......

I believe the above two boards are actually the same mainboard.

The Siemens board, labelled as (c) Dragon Data - Issue 2, using 16 Siemens 16x16K RAM to give 32K.
[/list]

Ahh the one with the stacked 18 pin chips.

There are 2 types of Mark II board:
The Mark II Board, labelled as DRAGON DATA LTD CPU UK 32K MKII - Issue 5 or Issue 6 - with the SAM mounted horizontally to make room for 16 RAM chips on the main board.

There does not appear to have been an Issue 1,3 or 4 board put into production.

I'll have a look see if there are any significant differences. (If I have both types of board), which will involve opening a few dragons...

The PSU board for the Dragon 32 comes in Issue 1,2,3 and 4. Issues 1 and 3 will be the most common and Issue 2 was withdrawn due to a modulator compatibility problem.

Not sure which versions I have I'll have to have a look at the ones that are not in machines (first) and will take some piccies.

As for the Dragon 64, I used to think there was only 1 board but recently I have seen two different D64 boards.....

I think both of mine are the same but then I've only actually seen the inside of two dragon 64s, are the Dragon 200 boards the same as the Dragon Data ones ?

Cheers.

Phill.

[Alastair]

If you wish to refresh your memories, the different types of Dragon board were discussed in the following thread viewtopic.php?f=5&t=110