Televideo 925 character rom dump

Guy Dunphy guykd at optusnet.com.au
Wed Apr 24 18:55:51 CDT 2019


At 08:14 AM 24/04/2019 -0700, you wrote:
>
>
>On 4/24/19 5:39 AM, Guy Dunphy wrote:
>
>> The keyboard controller is an 8049. Firmware not readable.
>
>8049s aren't protected. they are 2k versions of the 8048
>and can be read as 8749s

I did try reading it as an 8749. By 'not readable' I meant it read as all FF.
Using a Topmax device programmer; a fairly good brand.
Interestingly when I selected Intel 8749 it actually hung on reading. Repeatably. Never seen that happen before.
Selecting NEC 8749, it read, but got all FFs. 
Considering there's something odd going on, I was quite relieved to verify the chip still works afterwards.
I hadn't gone as far as getting out the databooks and checking whether 8049 should be readable.
I thought they are, but the absense of '8049' type in the chip programmer seemed to suggest otherwise. Unless they
were 'induced' to leave it out to hinder copying?
Shall look into it further.

Guy



More information about the cctalk mailing list