Horizon RAMdisk ROS and CFG Development

[Gary from OPA]

finally got around to upgrading my midwest card that was working fine, i stripped the ram off one of my old horizon 2000 boards that just is giving me headache, and stack up the chips on midwest one, and then i moved over the rambo as well, after i took the last picture i noticed i got the 259 chips in the wrong sockets for rambo, but swapped them and its working, so now i have 864k midwest with rambo working in one of my ti99 with another horizon with 486k on it, and in my other ti99 my horizon 4000 with 1536k, and a dead horizon 2000 and dead horizon 3000 both with no memory, and two older horizon 1000 (86) cards with 186k of 8k ram chips, one is dead, and other has ton of memory errors, but i don't need them for now. i might decide to sell off the 4 horizon boards i don't need, if anyone wants to spend time getting them going. at least now i have 3 perfectly working boards, and i can get to work resolving any remaining bugs, and doing some testing, and throwing my 2 cents again into the mix in improving ros/cfg.

[Gary from OPA]

The other day I won an PEB with flexcable and Horizon 4000B fully loaded (2mb) with 32k RAM as well for an amazing price of just under $230 CAD with all the shipping and taxes.

 

The card survived the trip ok, except the on and off switch broke off. -- no big deal. -- now the ony thing i got to do is remove the 32k ram addon -- i guess its enough just to remove the 32k chip and the 74ls support chip next to it.

 

and then i need to switch it over to use rechargeable batteries, it seems to be configured to use a set of alkaline ones instead. - that should be easy enough just remove the diode and add the 33 ohm resistor.

 

Now with this addition, since i upgraded my original horizon 4000 to full 2mb, i will have two cards at the 2mb level, and i need to get to work on fixing the rambo free space bug, that exists in 8.42c plus i want to do some more little improvements, finally getting everything up and running, took some time, but we moving ahead one step at a time.

 

 

[+Ksarul]

6 hours ago, Gary from OPA said:

The other day I won an PEB with flexcable and Horizon 4000B fully loaded (2mb) with 32k RAM as well for an amazing price of just under $230 CAD with all the shipping and taxes.

 

The card survived the trip ok, except the on and off switch broke off. -- no big deal. -- now the ony thing i got to do is remove the 32k ram addon -- i guess its enough just to remove the 32k chip and the 74ls support chip next to it.

 

and then i need to switch it over to use rechargeable batteries, it seems to be configured to use a set of alkaline ones instead. - that should be easy enough just remove the diode and add the 33 ohm resistor.

 

Now with this addition, since i upgraded my original horizon 4000 to full 2mb, i will have two cards at the 2mb level, and i need to get to work on fixing the rambo free space bug, that exists in 8.42c plus i want to do some more little improvements, finally getting everything up and running, took some time, but we moving ahead one step at a time.

 

 

Yep, that's a board I built. Note that those diodes are the Soviet D9K, which is the only current 1N34A equivalent out there that actually meets the spec. I still have some of those switches in my parts box. . .

[Gary from OPA]

4 minutes ago, Ksarul said:

Yep, that's a board I built. Note that those diodes are the Soviet D9K, which is the only current 1N34A equivalent out there that actually meets the spec. I still have some of those switches in my parts box. . .

i still have the bare 4000b prototype board that you mailed to me when I was in DR, the feds returned it a few months ago finally, so at some point I should order up parts and ram chips to build it up as well, but for now I got two 2mb 4000 boards working, this one you built, and original from Bud era, and two older horizon boards one 2000 type and one midwest type with rambo, and i still have 4 totally fucked up boards, one being 3000 and one being 2000 and two first batch 8k ones, but no luck getting those working, i might have to strip them all down and rebuild them from a bare board, they all in horriible conditions.