GMB's AMIGA Hardware-Tips
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I do not take any responsibility or guarantee for the work announced here.
Misc AMIGA Tips:
PCMCIA cards for the A1200/A600
Replacing the original A2000 PSU
A3000T and Cyberstorm
A3000T and GREX A4000T
Problems with Golden Image Mice
A4000T Tips:
Problems with the A4000T PSU Connector
Problems with the A4000T Battery of the Clock
Failing electrolytic capacitors in A4000T
Using the free SUB-D ports
Installing an external Floppy connector
Installing a mounting cage
Convertig the A4000T to a bigger tower case
Phase 5 Product Reworks:
Rework Cyberstorm MK2 from 040 to 060 Version
Rework Blizzard 2040 to 2060
If you have further tips and ideas for hardware-based enhancements or modifications of the A4000T (and other amiga models) and think that it should be shown here then write it to me.
This Page is still under construction (and probably will be forever)!
If your original A2000 PSU is irreparable, you can easily replace it with a standard PC-AT PSU. The main thing you have to do is to build an adapter cable that converts from the standard PC Motherboard connectors P8 and P9 to the amiga motherboard connector (5.04mm grid). You can fix the PSU by drilling 3 holes in the rear plate of the A2000 and mount it with some washer. Take a look for a propper power switch that fits into the original hole or build a plate where standard switches fit in and mount it with 2 screws in the original hole.
Does your A3000T crash several minutes after you powered on your System with a Cyberstorm accelerator card attached? If so you can probably solve this problem by adding a 74F08 into the free socket U103 next to the clock jumpers.
It is generally possible to use a GRex A4000T in an original A3000T. Therefor you only have to build a propper adapter cable on the electronics side that fits inbetween the PSU Plug and the motherboard. This should also provide the voltages required by the GRex board ( +5V, +12V, -12V, Power Good / Fail and of course Ground) on an AT-PSU plug (P8). On the mechanical side you have to cut the bottom plate of the 3.5 inch cage and bend it away to be able to fix a holder for the slot plates. The 3.5 inch cages are no longer usable as the plugs of the PCI cards require that space. The leads can either come out at the front through the 3.5 inch cage hole or could be redirected to the back of the tower. The A3000T PSU Plug is from MOLEX MINI-FIT series, Part No. 39012240 (Farnell 4138417) with PK100 contacts.
If you own an optical mouse from Golden Image, you may have noticed that the bottom of the mouse gets warm and that there are sometimes function failures. These problems do especially occur when you use a longer mouse cord that the short original one. This is because the hybrid IC inside cannot drive a long cord. The sollution is to install a line driver like the 74LS244 inside the mouse inbetween the PCB and the connector of the cord. With a line driver it is possible to drive mouse cords with several meters. You should also add two capacitors (for example a 100uF and a 100nF one) between the 5V power supply line and ground to stabilize the supply voltage.
There were calls since 23.07.2005.
