Some minor A500+/A590 mods

[Yulquen74]

Ok, a few minor A500+/A590 mods.


I wanted to use a PC power supply to power my Amiga 500+,
so I got a Corsair modular power supply. As I wanted to keep it on the
floor where it belongs, I put together a simple power control device
in a plastic box near the Amiga power connector. With the momentary switch,
a 1 second press toggles the power on and off. Green steady LED when turned on,
flashing red when turned off (I used a small PIC on a piece of veroboard inside the box to do that).
The power supply fan never spins since my setup draws so little power
compared to a full blown PC, which it is intended for.


Also, I wanted to get rid of the now flaky power supply for my A590, so I
did the well known mod and added the two power wires to the A590 mainboard to get
power from the A500 expansion bus. This hack is not recommended if theres a power
hungry beast of a hard-disk inside the A590, but I think I get away in my case since I use only a
low power SSD device, and I have also removed all RAM chips since I have the A500+ fully equipped with RAM.
Measuring the 5V and 12V rails inside the A590, even during continous read or write operations, the voltages are well within safe operating limits.


Having the A590 open, I added a flip-switch to turn on and off auto-booting.
The same switch is also available on the A590 DIP-switch panel, but a flip switch is much more accessible.
The switch connects/disconnects the CS# signal to the EEPROM chips. Thanks to the Guru-ROM firmware it is not dangerous
flipping the switch after boot because the PROM is only accessed briefly after reset, when it is copying itself to fast-RAM.


I also replaced Fred and Wilma with newer, more high intensity types to fresh
up the HD and power indicators.


At last, getting the A500+ online. Perhaps pointless on a (still) unaccelerated A500, but still...
I installed a Routerboard 411 inside the A500+. This is a very cheap linux based router delivered as a PCB,
and it is set up to using its serial port as a PPP server. Miami is set up to use a zero modem connection, and go online using PPP login.
The board is fastened to the A500+ top cover using plastic spacers with threads, which are glued to the cover using sikaflex.
I stole power (12V 200mA) from the floppy power cable. I also extended the boards RJ45 and DB9 connector to the back of the Amiga,
and use a loopback nullmodem cable between the Amiga and router serial ports. The RJ45 is connected to my local network using a LAN cable.


Pictures:

http://s1314.photobucket.com/user/y_...tml?sort=3&o=2

http://s1314.photobucket.com/user/y_...tml?sort=3&o=3

http://s1314.photobucket.com/user/y_...tml?sort=3&o=4

http://s1314.photobucket.com/user/y_...tml?sort=3&o=5

http://s1314.photobucket.com/user/y_...tml?sort=3&o=1

http://s1314.photobucket.com/user/y_...4e0b7.jpg.html

http://s1314.photobucket.com/user/y_...tml?sort=3&o=6

http://s1314.photobucket.com/user/y_...tml?sort=3&o=0

Some very interesting A500+ experiments you've done there.

Regarding the PSU, I've been thinking along the same lines for my desktop A1200 but I was wondering if I would be able to make a PIC controlled interface that would fit in between the keyboard flex-foil and the motherboard. Then I could have a pre-defined key combination to turn the power on or off. This could easily be done with a low power RF TX module.
The only thing is I don't think there's any standby power available inside the Amiga so there'd need to be battery backup on the interface. I'll let you know how I get on with that!

I would very much like to see a cheap accelerator made available for the A500. If it had on-board IDE as well it'd be a god-send.