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Author Topic: DKB 1202 and my new A1200...  (Read 1082 times)

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Offline jbuonaccTopic starter

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DKB 1202 and my new A1200...
« on: March 17, 2007, 05:28:05 PM »
grabbed an 'as-is' A1200 last week. turned out to be an Escom-era A1200HD with 3.1 ROM and a 262mb HD. while it's missing the trap door cover on the bottom, i was pleasantly surprised to see that it had the DKB1202 expansion with 4mb RAM installed. some questions/observations...

- i see there's room for a DSP chip. is the 68882 the only chip that will work with this? are there different mHz ratings to look out for? what will this do for me overall if installed? what's it doing for me as it is (if anything besides the 4mb RAM)?

- i'd like to maybe pull this out and try it in my other A1200 (3.0 ROM) to see what happens, but it doesn't seem like it wants to come out. sure doesn't feel like an A500 expansion that slides out nice, this thing feels like it's soldered in. haven't pulled off the shielding yet to check the connector. didn't seem like it wanted to budge, i wasn't about to force it.

- the battery was starting to corrode, so i pulled it. couldn't see any corrosion on the contacts, should be ok? i'll be replacing this.

- at first i thought the whole unit was toast. powered up to a black screen and a busy HD light. after a while it came up to the 'insert WB disk' screen - won't boot from the HD. one thing i noticed on power-up was a funny videogame sound coming from the unit itself (maybe i can record it if nobody knows what i'm talking about). my other one sure doesn't do this, sounds maybe like a bomb dropping in Missle Command or something. i don't know if this is a power-up sound they had programmed in or if it's trying to say something's wrong.

- i'm able to boot from a 3.1 disk that i have, but don't know enough to troubleshoot from there.

- i haven't tried swapping HD's between units, think this is worth a shot to maybe see what's up?





any advice would be greatly appreciated, still trying to figure everything out. thanks!

-justin.
 

Offline motrucker

Re: DKB 1202 and my new A1200...
« Reply #1 on: March 17, 2007, 08:42:53 PM »
Check out "http://www.amiga-hardware.com/" and look under RAM Expansion. It mentions the card, and may have pertinent info.
The card should come out without too much effort.
A2000 GVP 40MHz \'030, 21Mb RAM SD/FF, 2 floppies, internal CD-ROM drive, micromys v3 w/laser mouse
A1000 Microbotics Starboard II w/2Mb 1080, & external floppy (AIRdrive)
C-128 w/1571, 1750, & Final Cartridge III+
 

Offline Chain

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Re: DKB 1202 and my new A1200...
« Reply #2 on: March 17, 2007, 11:27:05 PM »
that one badly deformed shielding  8-)
too lazy to use shift key properly...
 

Offline rkauer

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Re: DKB 1202 and my new A1200...
« Reply #3 on: March 18, 2007, 12:10:10 AM »
The 68882 is not a DSP chip!

It is a FPU processor (Floating Point Unit). Look at your accelerator: there is a cristal in there? Grab an used (working, of course) 68882 with the same or higher clock (NEVER LESS).

A FPU may come handy for some (not so few) applications, but not for system's overall performance.

Oh, and ANY trapdoor card is "glued" or soldered in the main board. Try to pull it out again or look if the board are not locked in place by touching the floppy drive, for instance.
Goodbye people.

I\'ll pop on from time to time, RL is acting up.
 

Offline jbuonaccTopic starter

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Re: DKB 1202 and my new A1200...
« Reply #4 on: March 18, 2007, 08:17:18 AM »
Quote

Chain wrote:
that one badly deformed shielding


lol, yeah! they could've easily just bent it under and it would've looked fine. i took the shielding off and bent it underneath. looks a bit better i guess. updates...

- swapped the drive into my other A1200. got the same 'dead' noise on boot-up (this must be coming from the HD? or is it from the Amiga because it knows the HD is dead?). no action from the HD, but it immediately went to the 'load WB' screen. i'm guessing the delay on the other unit was due to it checking the RAM expansion? looks like the drive is shot, won't even come up in HDTools. sound right?

- when removing the shielding i had to pull the green ribbon cable for the keyboard. funny connector, does it just 'hold' the cable in there? just make sure the cable is in then press down to put it back in? don't want to screw that up.

- i was able to pull the RAM expansion, just needed to give it a bit of a gentle tug back and forth. had to remove the small RAM board to pull it out, hope i didn't zap anything in the process. any real point in getting the FPU for it? i'll be using the Amiga mainly for music/audio apps, sampling, sequencing, MIDI, etc as opposed to gaming/graphics/etc. will this help me at all? any idea what the max RAM that can be installed is?