m_thompson
Veteran Member
Maybe the Protective Overlay is work off of the tapes that we have been using?
We will try the alcohol swab on more tapes to see what we get.
We will try the alcohol swab on more tapes to see what we get.
The crew at the LCM sent us a listing of the kaleidoscope program that they use when demonstrating their PDP-12. I toggled it in and it works OK. Knobs 7 & 8 control the pattern on the display. If you fiddle with the knobs you can find settings that will cause a sequence of patterns to display.
You can watch the kaleidoscope program run here: https://youtu.be/_KZG_kE-K-0
Paul,
This is what they sent. It runs in LINC mode on the PDP-12, so it will be a bit of work to port it to a PDP-8.
LivingComputerMuseum.org
LINC ORG 4020 Kaleidoscope
4020 1020 LDA I,00 Load AC, full register
4021 0000 variable HLT Halt
4022 0343 SCR 03 Scale right N places
4023 0017 COM Complement AC
4024 1140 ADM 00 Add AC to memory (sum also in AC)
4025 0034 xxx xx xxxx
4026 1560 BCL I,00 Bit clear (any combination of 12-bits)
4027 4000 STC 0000 Store and clear AC (full address)
4030 4001 STC 0001 Store and clear AC (full address)
4031 2043 ADD 0043 Add memory to AC (full address)
4032 0141 DIS 01 Display point on oscilloscope
4033 1020 LDA I,00 Load AC, full register
4034 1777 variable DSC I,17 Display character on oscilloscope (2 x 6 matrix)
4035 0343 SCR 03 Scale right N places
4036 1140 ADM 00 Add AC to memory (sum also in AC)
4037 0021 XOA Extended Operations Buffer to AC
4040 1120 ADA I,00 Add memory to AC (index class)
4041 1400 SHD 00 Skip: Right half AC unequal to specified half of memory register Y
4042 1060 STA I,00 Store AC (index class)
4043 0000 variable HLT Halt
4044 0141 DIS 01 Display point on oscilloscope
4045 0103 0106 SAM 03 Sample analog chan N
4046 4051 STC 0051 Store and clear AC (full address)
4047 0107 0107 SAM 07 Sample analog chan N
4050 1120 ADA I,10 Add memory to AC (index class)
4051 0000 variable HLT Halt
4052 0451 APO Skip: Ac contains positive number
4053 6020 JMP 0020 Jump to register Y
4054 1560 BCL I,00 Bit clear (any combination of 12-bits)
4055 7774 JMP 1774 Jump to register Y
4056 0470 AZE not Skip: AC not equals 0000 or 7777
4057 6020 JMP 0020 Jump to register Y
4060 1120 ADA I,00 Add memory to AC (index class)
4061 0340 SCR 00 Scale right N places
4062 1040 STA 00 Store AC (index class)
4063 0022 xxx xx xxxx
4064 4035 STC 0035 Store and clear AC (full address)
4065 6020 JMP 0020 Jump to register Y
LINC docs are here: http://bitsavers.trailing-edge.com/pdf/washingtonUniversity/linc/ - because that's where Wes Clark and the LINC team ended up.
We found that there is a pair of bushings and spring on the motor shaft that take up the play and make the tape alignment more accurate. The lubricant on bushings and shaft had dried out and was sticky