> On 05/15/2022 11:02 PM John Ball via cctech wrote:
>
>
> I just received a machine that someone found at a Vancouver second hand
> store that I basically told them to buy on the single fact I don't own any
> COSMAC machines and I've now had a chance to take it apart and photograph
> the boa
On 5/15/2022 4:16 AM, Eric Smith via cctalk wrote:
On Sat, May 14, 2022, 16:09 ben via cctalk wrote:
On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote:
AFAIR LS can only drive one unit TTL load.
paul
LS is 4 TTL, 4 ma low.
Was there a trick of forcing the output of D flip fl
On 2022-May-15, at 3:53 PM, Eric Smith wrote:
> On Sun, May 15, 2022, 13:03 Brent Hilpert via cctalk
> wrote:
> On 2022-May-15, at 1:16 AM, Eric Smith via cctalk wrote:
> > On Sat, May 14, 2022, 16:09 ben via cctalk wrote:
> >> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote:
> >>>
On 2022-May-15, at 3:53 PM, Eric Smith wrote:
> I specifically said 74x74. Early TTL flipflops were very crude by
comparison.
On Mon, May 16, 2022 at 11:28 AM Brent Hilpert via cctalk <
cctalk@classiccmp.org> wrote:
> pre-TTL != early TTL
>
No, but 7470, 7472, 7473, and 74948 were _very_ early
> -Original Message-
> From: cctalk On Behalf Of Rick Murphy via
> cctalk
> Sent: 16 May 2022 17:28
> To: cctalk@classiccmp.org
> Subject: Re: Replacement for a DEC 7474 Chip
>
> On 5/15/2022 4:16 AM, Eric Smith via cctalk wrote:
> > On Sat, May 14, 2022, 16:09 ben via cctalk wrote:
>
> On May 16, 2022, at 4:59 PM, Rob Jarratt via cctalk
> wrote:
>
>> I have several 7474s, including one marked DEC 7474. Sadly, I fear that
>> shipping from the US is likely to be prohibitive.
>
> I have ordered some 7474s. However I am getting a bit lost in the discussion
> now. From a sim
I have a puzzlement with my IBM 1410 FPGA implementation.
ALD page 42.10.10.1, ILD figure 89
The symptom is this: The CPU runs and can execute instructions. So,
stuff is generally working.
Starting the address set process, the console appropriately prints the
"B" prompt (to set the instruct
You are right, I thought I remembered someone else saying on this thread
that he couldn't find a datasheet for the 7474 so I didn't look, but
actually I found one quite easily!
From: Paul Koning
Sent: 16 May 2022 22:08
To: r...@jarratt.me.uk; Robert Jarratt ;
cctalk@classiccmp.org
Cc: Rick Mu
On 2022-05-16 1:50 p.m., Eric Smith via cctalk wrote:
On 2022-May-15, at 3:53 PM, Eric Smith wrote:
I specifically said 74x74. Early TTL flipflops were very crude by
comparison.
On Mon, May 16, 2022 at 11:28 AM Brent Hilpert via cctalk <
cctalk@classiccmp.org> wrote:
pre-TTL != early TTL
