Re: How to transform a Disk II card to handle 13-sec?

[wmeckling <meckling@comcast.net>]

On Feb 9, 5:19 pm, Toinet <antoine.vig...@laposte.net> wrote:
> Hi There,
> I recently purchased a set of 2 "boards" which allow to switch from a
> 13-sec to a 16-sec format (http://cgi.ebay.com/ws/eBayISAPI.dll?
> ViewItem&item=310290628060)
>
> As I own two Disk II controller cards, I would like to move the 13-sec
> chips from the above switch card to one of the Disk II controller
> cards but I need help.
>
> IIRC (because I am unable to get the exact page on hackzapple.com),
> there are two chips that must be changed (the bootstrap ROM and the
> LSS ROM) but two questions arise:
> - which ones should I move? I don't know if the info given on the
> auction page is correct
> - once changed, is that sufficient? I mean, will I get a 13-sec Disk
> II controller card?
>
> Thanks for your help,
>
> antoine

Antoine
What you have essentially purchased is a set of 13 sector proms (P5
and P6) and 16 sector proms (P5A and P6A) with a switch that lets you
switch between them. The 13 sector proms are marked P5 (341-0009) and
P6 (341-0010) while the 16 sector proms are marked P5A (341-0027-A)
and P6A (341-0028-A), they might not have the -A after the 27 or 28.
Once you have installed the P5 and P6 on your Disk ][ controller in
place of the P5A and P6A use the routine that Dave supplied to verify
the code once the proms are installed. Use caution when removing and
reinserting the proms since the legs are delicate.
Good luck
wm