AT&T 6300 - bars on screen

[billdeg]

I have an AT&T 6300 that when it boots "bars" appear on the screen. AT&T monochrome monitor

1. turn on system
2. one beep
3. cap lock and num lock lights blink a little bit
4. vertial bars appear on screen. If you could imagine the ascii character for a block, stacked in vertical rows (not bad monitor)

I have noticed that there are some fans of this system here.

Anyone seen this before?

Bill

 

[digger]

Does the machine make any attempts to boot from a drive after that beep, even though you don't see anything but the bars on the screen?

 

[Trixter]

it's a display adapter problem (probably the RAM on the display adapter). Does it continue to boot, or lock up?

 

[Yzzerdd]

I'd say it's most likely the display adapter, but it very well could be one of the BIOS chips. I have the same question as the others: Does it boot? I've got a display adapter here at the house (deep in the pile) for the AT&T PC 6300 if you're interested, tested good.

--Jack

 

[billdeg]

And now it works.

And now it works.

OK. In response to your question of "does it boot" - I plugged it in, turned it on and now it more or less works. For two years it did not work, and now it does.

http://www.vintagecomputer.net/att/pc_6300/

thanks for the good vibes. One issue - when it boots I get "no fixed disk present" or something like that yet it still eventually finds the hard drive and boots to the DOS 4 shell. I will work more on this later...

Bill

 

[Trixter]

One issue - when it boots I get "no fixed disk present" or something like that yet it still eventually finds the hard drive and boots to the DOS 4 shell.

There is a dip switch for whether or not an external hard disk bios is present. If it is set to "yes" (don't remember exact terminology/settings, sorry), then the internal BIOS code is disabled; if set to "no" then generic BIOS code is initialized. It sounds like your HD card has an onboard BIOS so that's why the POST says "no hard disk" but yet it boots.

Just a hunch; I could be wrong.

 

[Yzzerdd]

There is a dip switch for whether or not an external hard disk bios is present. If it is set to "yes" (don't remember exact terminology/settings, sorry), then the internal BIOS code is disabled; if set to "no" then generic BIOS code is initialized. It sounds like your HD card has an onboard BIOS so that's why the POST says "no hard disk" but yet it boots.

I agree. Generally when the fixed disk is external or is a hardcard, the AT&T PC 6300's BIOS needs to be told it has an "External boot ROM" for the hard disk.

Bill, try this:
On switch set SW-1, change SW3 to it's opposite setting, then try booting. If you have the system upside down and the disk drives are towards you (and the fan on the opposite end) then SW-1 is the lower set of switches(plus, it's labeled SW-1 in really small print).

--Jack