Re: [Simh] Non-numeric character in IBM 1620 P & Q addresses

2015-12-24 Thread Paul Koning
> On Dec 23, 2015, at 4:30 PM, Bob Supnik wrote: > > There's nothing conditional about the user documentation. The 1965 reference > manual says, "MARS (Memory Address Register Storage) Check Light. This light > is turned on when a digit in MARS has a parity error or an

Re: [Simh] Non-numeric character in IBM 1620 P & Q addresses

2015-12-24 Thread Bob Supnik
It's worse than that. The detailed logic is shown on 227-5631-0 pp 188ff. The decode chart for each decode switch (DSW) is: DSW 0 DSW 10001 DSW 20010 DSW 3X011 DSW 4X100 DSW 5X101 DSW 6X110 DSW 7X111 DSW 81XX0 DSW 9

[Simh] PDP-11 BASIC, booting the hard way

2015-12-24 Thread Will Senn
All, Thanks for the comments and feedback on the bootstrap loader analysis. I have edited it to reflect the input I received, but it is still a work in progress. I will continue to refine it as my understanding of the area expandes. Here is the related, simpler, writeup of booting PDP-11

Re: [Simh] Feasibility of connecting physical LK to emulated LK device

2015-12-24 Thread lists
On Wed, 23 Dec 2015 23:51:47 -0800 (PST) b...@gewt.net wrote: > As it is largely just serial, I can think of museum displays this could > benefit (next pet project: SDL in a console framebuffer) due to the > simple adapter needed (http://www.wickensonline.co.uk/vaxen/linuxLK.html) > > Thoughts?

Re: [Simh] Writeup of PDP-11 bootstrap loader analysis

2015-12-24 Thread Johnny Billquist
Will, you got it. :-) I didn't check through my inbox before writing my replies, and Paul already put you on track. Johnny On 2015-12-24 05:30, Will Senn wrote: On 12/23/15 5:09 PM, Johnny Billquist wrote: As for your analysis: Your explanation of branches seems somewhat over

Re: [Simh] Writeup of PDP-11 bootstrap loader analysis

2015-12-24 Thread Johnny Billquist
On 2015-12-24 02:02, Will Senn wrote: On 12/23/15 5:09 PM, Johnny Billquist wrote: As for your analysis: Your explanation of branches seems somewhat over complicated. The instruction is indeed in just 8 bits, while 8 bits are the offset. However, there is no need to mess things up with

Re: [Simh] Writeup of PDP-11 bootstrap loader analysis

2015-12-24 Thread Johnny Billquist
On 2015-12-24 02:02, Will Senn wrote: On 12/23/15 5:09 PM, Johnny Billquist wrote: As for your analysis: Your explanation of branches seems somewhat over complicated. The instruction is indeed in just 8 bits, while 8 bits are the offset. However, there is no need to mess things up with