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Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 6:10 pm
by zephyr
There are three types of PSU board, and four types of mainboard.
PSU's can be identified by the type of modulator used. The model number being clearly marked on the top as follows:
MK1 - 1286 Modulator
MK2 - 1233 Modulator
MK3 - 1287 Modulator
CPU's can be identified by comparing the RAM area with the descriptions (oldest design first) below:
(1) Piggy Back - 6 chips on main board, piggy back board in sockets 1 and 8, 11 chips on piggy back board
(2) OKI - 8 RAM chips (usually labelled OKI)
(3) Siemens - 1 row of 16 RAM chips, 2 chips per socket (one chip on top of another)
(4) 16x16 - Two rows of RAM chips, 1x9 and 1x7
Look under "publications\Technical\Dragon 32 - REPLACEMENT OF POWER SUPPLY AND CENTRAL PROCESSING UNITS ON THE DRAGON 32" for more information.
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 6:20 pm
by Vato
Thanks, Zephyr! I'll check that out.
One question though.....
if there are four versions of the mainboard, then why is mine marked "Issue 5" and "Issue 6" ? Doesn't that imply that there must be at least six versions, or am I missing something crucial?
Vato
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 6:25 pm
by zephyr
No, AFAIK all issue 6 boards are just slightly modified versions of the issue 5 (16x16 - Two rows of RAM chips, 1x9 and 1x7) board.
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 7:13 pm
by Vato
Ok, I now have updated the database with a powerboard field, and added instructions on how to tell them apart.
I have left the mainboard choices as thy were (from Issue 1 to Issue 6), as it's easier to read the issue no. from the markings, than from the RAM setup.
Sould we say it's ready then? Or are there any other things I should consider?
Thanks for the help everyone!
Vato
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 8:44 pm
by zephyr
There's a mistake in the 'Crystal speed' selection. You have typed it as 14.21818 MHz instead of 14.31818 MHz.
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 8:45 pm
by Vato
zephyr wrote:There's a mistake in the 'Crystal speed' selection. You have typed it as 14.21818 MHz instead of 14.31818 MHz.
whoopsie.... fixed!
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 8:47 pm
by zephyr
I'll dig out one of my Dragon 32's later and give it a try...
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 9:21 pm
by admin
All,
If I recall correctly, the 4 different RAM combinations do not directly map onto issue numbers.... Issue 5 is the most common and was available with at least 2 of the RAM combinations and maybe more.
So it might be worth adding this as another field....
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 9:25 pm
by admin
Also.... The TANO powerboard is in a class of its own (being US based).....
and there are different boards with different PAL based RF Modulators to cater for other countries (I have at least one of these somewhere)
Re: Dragon survey, what to ask for?
Posted: Tue Jun 16, 2009 9:33 pm
by zephyr
I just spent an age typing extra comments and it wiped everything out , and offered to take me to the start just because I didn't leave my email address.
That's not going to go down well with anyone!!!