BloodyCactus
Member
desoldered my 23pin sockets m/f from my donor a500 mobo.. man that was a *****, even with the heat gun. that ground plane just sucking up the heat.
GBA1000 rev4 Build Log
- Thread starter BloodyCactus
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yamakakiche
New member
I'm doing my shopping list...
Have you found a distributor for:
- DS1488 (IC44) in DIP package ? In SOIC in FARNELL yes...
- DS1489 (IC45) in DIP package ? In SOIC in FARNELL yes...
- MPF102 (T1,T2) or équivalent ? On ebay yes but expensive.
- MSM6242 (IC39) ?
- MSM514221 (U470, U471, U472) ?
- UPD42101 (U473, U474, U475,U479) ?
- a ref for the PSU connector on the board ?
-for the LM339, we can put a 300ns or the 1,3us ?
@BloodyCactus you can cut the layer with a good cutter for the dissipation. After it's more easy with the heat gun.
Have you found a distributor for:
- DS1488 (IC44) in DIP package ? In SOIC in FARNELL yes...
- DS1489 (IC45) in DIP package ? In SOIC in FARNELL yes...
- MPF102 (T1,T2) or équivalent ? On ebay yes but expensive.
- MSM6242 (IC39) ?
- MSM514221 (U470, U471, U472) ?
- UPD42101 (U473, U474, U475,U479) ?
- a ref for the PSU connector on the board ?
-for the LM339, we can put a 300ns or the 1,3us ?
@BloodyCactus you can cut the layer with a good cutter for the dissipation. After it's more easy with the heat gun.
BloodyCactus
Member
Massimo_It
Member
The original psu connector has square pin with 3,96mm pitch, i don't have other information.
For gba1000 board i used a molex connector kk series 41791 model, fit well in the board.
Probably are the same but i don't sure.
MC1488 and DS1488 are equivalent, see CBM Approved Cross Reference
http://www.amiga-stuff.com/hardware/cbm-approved-cross-reference.html
For the other parts listed probably only ebay or hard-to-find supplier.
For gba1000 board i used a molex connector kk series 41791 model, fit well in the board.
Probably are the same but i don't sure.
MC1488 and DS1488 are equivalent, see CBM Approved Cross Reference
http://www.amiga-stuff.com/hardware/cbm-approved-cross-reference.html
For the other parts listed probably only ebay or hard-to-find supplier.
Massimo_It
Member
Preamble: my skill in electronic are not much then i can be wrong but i tried to do some reasoning on the parts with unknown value.
This parts is: L104, R135, R136, R137 and R138.
L104 : In the board were used 2 types of ferrite bead. One is the 48 OHM/6A that is used for the powers line: VCC, -5v and +12v.
The other type is the 150 OHM that is used for the rest, i think that L104 use this type.
Note that L104 is connected on the GND.
R137 and R138 : these resistors is used for the x8 connector, this is an internal connector audio.
Also in the Rev5 board these are sign with (n.b.), this section is the same of rev4 board.
I think that if we not going to use this connector can leave this pads empty.
R136 : I think that i a resistor wit a value of 1K5. In the rev5 board schematic say this.
The section are the same in both the revision board (rev4 and rev5).
R135 : For this i haven't idea. The rev5 board in this section is totally different.
Everything i can tell is that IC78 (74AC74) takes the signal of ic61 (cpu oscillator), process it and put them into CPUCLK.
Please let me known what you think.
This parts is: L104, R135, R136, R137 and R138.
L104 : In the board were used 2 types of ferrite bead. One is the 48 OHM/6A that is used for the powers line: VCC, -5v and +12v.
The other type is the 150 OHM that is used for the rest, i think that L104 use this type.
Note that L104 is connected on the GND.
R137 and R138 : these resistors is used for the x8 connector, this is an internal connector audio.
Also in the Rev5 board these are sign with (n.b.), this section is the same of rev4 board.
I think that if we not going to use this connector can leave this pads empty.
R136 : I think that i a resistor wit a value of 1K5. In the rev5 board schematic say this.
The section are the same in both the revision board (rev4 and rev5).
R135 : For this i haven't idea. The rev5 board in this section is totally different.
Everything i can tell is that IC78 (74AC74) takes the signal of ic61 (cpu oscillator), process it and put them into CPUCLK.
Please let me known what you think.
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yamakakiche
New member
Good deduction for L104, R137, R138 and R136.
Can we use an ATX PSU with adaptator in place of original PSU ?
Can we use an ATX PSU with adaptator in place of original PSU ?
Massimo_It
Member
Yes, on the board there a jumper (x16) for select where get the tick signal.
Jumper pin 1 and 2 for tick supplied from psu, jumper pin 2 and 3 for signal /VSYNC from CIA. Same as A2000 and A3000.
yamakakiche
New member
Great !
Thanks Massimo for this info.
Thanks Massimo for this info.
Massimo_It
Member
yamakakiche
New member
Good job !
For the rest of people who have buy a board, what's your progress ?
For the rest of people who have buy a board, what's your progress ?
Massimo_It
Member
I have to solder all connector, all resistor network, battery holder, two capacitor trimmer, Q1, T1, T2, T3 and all jumper and off course the mysterious parts.
Once this is done i have finished the job solder on the board.
When all is soldered i can put the ic socketed, many i have already, some i've bought and wait them.
I have still to buy: Oscillator 100Mhz, Gals and LSI1024. For the rest i should have it all.
Once this is done i have finished the job solder on the board.
When all is soldered i can put the ic socketed, many i have already, some i've bought and wait them.
I have still to buy: Oscillator 100Mhz, Gals and LSI1024. For the rest i should have it all.
Has anyone come up with a final BoM for this board? I have the board, and all the parts that Kipper2k provided, but I'm not completely sure what else that I need, beyond what a donor A500 can provide.
If anyone else, who is further along, could comment, it would be of great assistance.
Thanks!
- Alex
If anyone else, who is further along, could comment, it would be of great assistance.
Thanks!
- Alex
Massimo_It
Member
Not yet but someone (not me) is working for the BOM with parts code.
However the BOM of rev.1 board is good for rev.4 board except for R74 and R75 that were removed. The rev.4 board have also some parts more.
I have been working on a spreadsheet that takes the Partlist from the schematic and details the component sources such as Digi-Key, Mouser, Jameco, or donor boards like A500, A1000, and A3000. Each component is hyper linked to the suppliers website for ordering or a donor board (orientation). It is about 85% completed, but requires a thorough clean up and validation of its contents before I would feel remotely good about releasing it out to anyone. It will also have a suggestive build order for components and hopefully a trouble shooters guide for all known issues for building and testing.
Thanks to Massimo_It and others who have shared their information with me. Still needing donor information, so if you have any please share.
Mike
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Firedawg 
That's awesome
That's awesome
Damn, purchased what was supposed to be a non-working, broken, damaged, about to be thrown in the trash Amiga 500 only to find out today that it works just fine. I was about ready to take it a part to begin my component mining operations, but for grinds and giggles I decided to power it up, and would you know it started right up. I cannot knowingly destroy this computer, so now I'm going to have to find another source for my much needed GBA1000v4 parts.
