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The ET-11967 Service Module - ThomasF - 05-28-2024 06:46 PM
Hi all,
While looking at the Service Module (SM-1C), I raised some questions about the test of peripheral flags.
The answer (that I had missed from the documentation) was the use of the ET-11967 FI-wired module.
It is described in another post that "This ET-11967 module is a double memory module which fills both ports 3 & 4 address range and has FI line active".
While trying to implement this module on the Pico board, I stumbled upon some questions while disassembling the code and trying to understand the inner workings of this module.
In short - I have now successfully executed the IO service test on a real HP-41 with the Service Module loaded and the ET-11967 module emulated, and to get this to work I had to abandon the description above.
Firstly, the FI-line is not just active, it is in reality a copy of the DATA line. I think (without having a module to test with), that the FI and DATA pins are just shorted in the module, so that any data on the DATA pin is copied to the FI line.
This is how I implemented the ET-11967 in the Pico - just copy the DATA to the FI line when a Service Module is plugged in.
Secondly I doubt that this is a "double memory module" - I belive it is only a single memory module only.
While developing the code for the ET-11967 I tested it on a HP-41CV, and I could verify that the peripheral flag test worked ok, but the memory test failed - I just got "IO PORT TEST FAILED".
Looking through the code, I found the test code and it loops 4 times, writing and reading at address 0x100, 0x140, 0x180 and 0x1C0 - which corresponds to the addresses of the 4 memory modules that fits in the calculator.
And according to the ínstructions in the module manual, the Service Module should be in port 3, the ET-11967 in port 4, and a single memory module in both port 1 and 2.
This made us belive that the ET-11967 is a double memory module, so that we have full memory in the calculator and the service module could test them all.
I equipped a HP41C with no memory modules and the Pico (with Service Module and the ET-11967 emulated).
Running the IO test resulted in "1,2,3,4, FAILED".
WIth two memory modules inserted I got "3,4, FAILED".
As expected, since I don't have any memory emulation in the Pico for this setup.
But why did the HP41CV fail? It should have all the memory needed?!?
Disassembling the test code revealed that there is a loop, which writes and reads from the adresses above (writes a value, reads it back and compare - if equal the memory exists).
If the test fails - it will increment a counter, and after the test, this counter is tested against .... 1 !!
So, for the test to work, the loop must fail once!
I loaded my HP41C with three memory modules and executed the test again - and voila - "IO PORT TEST OK"!
So, my interpretation of these results and tests shows that the ET-11967 is NOT a double memory module, but a single memory module with the FI and DATA pins connected.
Is there anyone out there who have access to these two modules and could try the IO test (EEX) in a HP41CV?
Or if someone have made a double memory module to try that with the service module (SM1C) in a 41C with two memory modules? My expectation in that case is that the test should work with only one memory module ... (but the test will fail if the DATA and FI are not connected).
So, in summary, the description of the module should be that "This ET-11967 module is a single memory module which fills port 3 address range and has FI connected to DATA pin".
If someone is interested I could provide traces from executing the IO test in a CV or C with 3 memory modules.
Cheers,
Thomas
This is the code for the complete IO port test in Servioce Module SM-1C.
It only checks the peripheral flags according to a pattern in register C, and then writes and read from 4 addresses, of which one (and one only) must fail, then reports the result.
Code:
; Execute IO test (key EEX)
45FB 33111C ?NCXQ 47CC ; Display " TEST"
45FD 09D11C ?NCXQ 4727
45FF 014 ; 'T'
4600 012 ; 'R'
4601 00F ; 'O'
4602 010 ; 'P'
4603 020 ; ' '
4604 00F ; 'O'
4605 109 ; 'I'
4606 24111C ?NCXQ 4790 ; Delay 0.7 seconds
4608 27D108 ?NCXQ 429F ; Set B[M] to 000FFFFFFFF
; Load C with a test pattern for FI signal
460A 04E C=0 ALL
460B 2DC R= 13
460C 3D0 LD@R F
460D 3D0 LD@R F
460E 3D0 LD@R F
460F 3D0 LD@R F
4610 09C R= 5
4611 3D0 LD@R F
4612 3D0 LD@R F
4613 3D0 LD@R F
4614 01C R= 3
; C = FFFF0000FFF000
; This needs a FI-wired module so that the C-reg is
; feed back into FI so that the flags could be checked!
; With the pattern above flag 0,1,2,6,7,8 and 9 should be active
4615 3AC ?FI= 0
4616 0DB JNC +27 4631
4617 32C ?FI= 1
4618 0CB JNC +25 4631
4619 22C ?FI= 2
461A 0BB JNC +23 4631
461B 02C ?FI= 3
461C 0AF JC +21 4631
461D 06C ?FI= 4
461E 09F JC +19 4631
461F 0AC ?FI= 5
4620 08F JC +17 4631
4621 16C ?FI= 6
4622 07B JNC +15 4631
4623 2AC ?FI= 7
4624 06B JNC +13 4631
4625 12C ?FI= 8
4626 05B JNC +11 4631
4627 26C ?FI= 9
4628 04B JNC +9 4631
4629 0EC ?FI= 10
462A 03F JC +7 4631
462B 1AC ?FI= 11
462C 02F JC +5 4631
462D 36C ?FI= 12
462E 01F JC +3 4631
462F 2EC ?FI= 13
4630 01B JNC +3 4633
; If we reach here - some flags were failing!
4631 022 B=0 @R ; B = .00FFFFFFF0...
4632 188 SETF 11 ; Set flag to indicate FI failure
4633 05E C=0 MS
4634 3F0 PRPHSLCT
4635 236 C=C+1 XS
4636 0A0 SLCTP
4637 3DC R=R+1
4638 10E A=C ALL
4639 270 RAMSLCT
463A 2F0 WRITDATA ; Write to a memory address
463B 04E C=0 ALL ; Clear C
463C 038 READDATA ; Read back from same address
463D 36E ?A#C ALL
463E 02B JNC +5 4643 ; Jump if equal (address exist)
463F 17E A=A+1 MS ; Increment A[MS]
4640 0AE A<>C ALL
4641 10E A=C ALL ; C = A
4642 022 B=0 @R
4643 0E0 SLCTQ
4644 31C R= 1
4645 130140 LDIS&X 140
4647 20A C=C+A R<
4648 373 JNC -18 4636
4649 0A0 SLCTP
464A 309118 ?NCXQ 46C2 ; Turn display on
464C 05E C=0 MS ; C[MS] = 0
464D 23E C=C+1 MS ; C[MS] = 1
464E 37E ?A#C MS
464F 0FF JC +31 466E ; Jump if A[MS] != 1 (error)
4650 05C R= 4
4651 052 C=0 P-Q
4652 272 C=C-1 P-Q
4653 0F2 B<>C P-Q
4654 18C ?FSET 11 ; Check FI error flag
4655 0CF JC +25 466E ; Jump if FI flag test failed ...
4656 14D11C ?NCXQ 4753 ; Display " OK "
4658 328 WRIT 12
4659 328 WRIT 12
465A 09D11C ?NCXQ 4727
465C 013 ; 'S'
465D 014 ; 'T'
465E 012 ; 'R'
465F 00F ; 'O'
4660 010 ; 'P'
4661 120 ; ' '
4662 24111C ?NCXQ 4790 ; Delay 0.7 seconds
4664 3CC ?KEY
4665 1DD103 ?CGO 4077
4667 18C ?FSET 11
4668 027 JC +4 466C
4669 2CC ?FSET 13
466A 3ED117 ?CGO 45FB
466C 201102 ?NCGO 4080
; Jumps here if failed
466E 2DC R= 13
466F 188 SETF 11
4670 290 LD@R A
4671 235118 ?NCXQ 468D ; Fill A with "C6F1F2F3F4"
4673 0C6 ;
4674 0F1 ;
4675 0F2 ;
4676 0F3 ;
4677 1F4 ;
4678 08111C ?NCXQ 4720
467A 006 ; 'F'
467B 001 ; 'A'
467C 009 ; 'I'
467D 00C ; 'L'
467E 005 ; 'E'
467F 104 ; 'D'
4680 313 JNC -30 4662
4681 1B0 POPADR
4682 31C R= 1
4683 3EE LSHFA ALL
4684 3EE LSHFA ALL
4685 330 FETCHS&X
4686 10A A=C R<
4687 23A C=C+1 M
4688 2F6 ?C#0 XS
4689 3D3 JNC -6 4683
468A 170 PUSHADR
468B 0AE A<>C ALL
468C 3E0 RTNRE: The ET-11967 Service Module - Didier Lachieze - 05-28-2024 07:31 PM
(05-28-2024 06:46 PM)ThomasF Wrote: So, in summary, the description of the module should be that "This ET-11967 module is a single memory module which fills port 3 address range and has FI connected to DATA pin".
Great deep dive and analysis of this service module !
Does this means that an ET-11967 Service Module could be built from a modified 82106A single memory module where B3 would be internally forced to 0 and DATA connected to FI?
RE: The ET-11967 Service Module - ThomasF - 05-28-2024 08:25 PM
(05-28-2024 07:31 PM)Didier Lachieze Wrote:(05-28-2024 06:46 PM)ThomasF Wrote: So, in summary, the description of the module should be that "This ET-11967 module is a single memory module which fills port 3 address range and has FI connected to DATA pin".
Great deep dive and analysis of this service module !
Does this means that an ET-11967 Service Module could be built from a modified 82106A single memory module where B3 would be internally forced to 0 and DATA connected to FI?
Hi Didier,
Yes, that is my conclusion, with the disclaimer that I have not been able to verify the connections since I have no module myself.
But hopefully someone with a real ET-11967 could measure on these pins to verify this.
Cheers,
Thomas
RE: The ET-11967 Service Module - ThomasF - 05-30-2024 04:54 PM
Hi again,
Curiosity wins sometimes - so I disassembled a single memory module, lifted the B3 pin, and made a shortcut between DATA and the FI pin.
With two memory modules in port 1 and 2, my Pico with Service Module SM-1C in port 3 and the DIY "ET-11967" in port 4, I can now run the IO PORT TEST with success!
There is no emulation of the ET-11967 in the Pico, it just hold the ROM for the Service Module at 0x4000.
(05-28-2024 07:31 PM)Didier Lachieze Wrote: Does this means that an ET-11967 Service Module could be built from a modified 82106A single memory module where B3 would be internally forced to 0 and DATA connected to FI?
So the answer should be yes, and very easy to do so (with no problem to restore the module again) ...
Cheers,
Thomas
RE: The ET-11967 Service Module - Didier Lachieze - 05-30-2024 06:31 PM
Great ! Thanks for checking.