The system now functions as originally intended and does its job very satisfactorily.
The experimenter relies heavily on the main computer center for data processing.
In assembling this system now, one would buy the disk already interfaced by the computer manufacturer; furthermore the manufacturer now offers programs that would greatly reduce the programming costs.
A memory scope would eliminate the need for a disk-to-CRT display interface.
Less-expensive magnetic tapes are now available. However, it would be better to buy the tape already interfaced by the manufacturer of the computer.
The added cost of buying a 16-or 18-bit computer would have been almost completely offset by savings in the cost of programming.
The addition of a fast printer (e.g., Inktronic $5600) would have paid for itself in time saved during programming but would not be of much use in experiment.
4. Costs
The costs of the PDP-8 are given in Table 2.
| TABLE 2 System Costs PDP-8—1967 | ||
| Costs | Man-Months | |
| CPU, 4k, 12-bit | $18,000 | - |
| Data disk | 8,300 | - |
| Disk interface | 2,500 | 6 |
| CRT display control | 1,000 | 1 |
| CRT | 700 | - |
| Mag tape (556 BPI, 30 IPS) | 8,800 | 0 |
| Mag tape interface | 2,000 | 6 |
| Misc. interfaces | 2,700 | 12 |
| 8 scalers (on loan) | - | - |
| ADC (4096-channel, 35-µsec dead time) | 2,500 | - |
| 8-parameter input to ADC (analog multiplexer) | 1,500 | - |
| Remote console (switch panel) | 300 | - |
| Time-of-day clock | 1,000 | - |
| $49,300 | ||
| Systems programs | 12 | |
| Data-handling programs | 12 | |
| Engineering diagnosis, debugging | 9 | |
| 58 | ||