TRS-80 Model IV PALs

[Eric Smith]

On Wed, Dec 4, 2019 at 11:08 PM rescue via cctalk <cctalk at classiccmp.org>
wrote:

> I have a TRS-80 Model III with a IV upgrade in it (non gate array).
> I have a hunch that one or two of the HALs are bad (the primary one
> Anyone know if these can be read, or if they are protected (for
> example, if I were able to borrow some working ones, could they be
> duplicated ?) ?


Last year I read most of the PALs and HALs of a TRS-80 Model 16B main board
(same as Model 12 main board). I was surprised that none of the PALs were
protected, and even more surprised that some (but not all) of the HALs
could be read as PALs.