The DEC Engineers have finished the machine re-wiring, and the system is working again. We have discovered that RSX+3 requires the Memory Relocate option, which is on order. DEC will therefore ask Maynard if this option can be shipped early so that we can use the software now. Failing this, DEC will let us have a copy of RSX+ to use.
It has been found in practice. that the use of text arguments in PR,AR is unhelpful. Since index variable names used elsewhere (in LOAD etc) are real numbers (converted from text by ANAME), it is usual to use FORTRAN variables, setting the real number values initially. In this way, it is possible to forget about the text name altogether, and just use the numbers, except for PR,AR arguments. Thus the form of these arguments will be changed to accept real numbers also.
The contour package obtained from John Lewis appears to work. It will therefore be included as a high-level routine suite, with an extra option to remove the dot matrix. The hardware character set appears adequate.
Some attempts have been made to unite generalised pan and zoom routines. These have shown up some system deficiencies. After considerable discussion, we decided
a) User must specify which region is to be altered to provide pan or zoom.
b) Routines must be provided to shift region R by DX,DY, expand region R by EX,EY about its centre, and rotate region R by RXY. This last routine will make use of the region shape parameters to provide rotating regions.
c) Pans should use 'ease-in', 'ease-out' for smooth moves, zooms need to be logarithmic to appear even.
When making films, it is often necessary to duplicate frames, and so some means of saving the calculated orders are needed.
STSAV (filename, device)
sets up a file for saving basic orders for a device. It cannot be used with STDF. Considering SD4020 output as an example, all subsequent output will go to file, rather than the device.
FISAV
will finish the saving, set the file type to '- device number' and save the number of frames (ADVFLM orders). When this file is DRAWn, output will be sent directly to the device specified, if selected, and no sequence list activity will be started. The frame count will be incremented correctly.
The following points are made about the design of the film:
a) The film is intended to show what facilities SPROGS has to offer. No voice sound track is envisaged, but cued music is possible.
b) 16mm frames fit in a centred 3 x 4 rectangle.
c) Wording should be cut to a minimum, preferably appearing on a separate frame before the action.
d) Fi1m will run at 24 frames per sec. A rough guide to title timing can be obtained by reading the title twice slowly.
e) Small changes to a picture must be highlighted or they will pass unobserved. Items must not flash onto the screen while the viewer is trying to read text.
The use of LCPRY is still causing problems. As no satisfactory solution has yet been found, these problems are stated again here.
The main use of LCPRY is to expand DRAW such that the basic orders from DRAW are stored in the current file rather than the DRAW itself. The previous note suggested a change such that the value of LCPRY be retained throughout a file definition. However, DRAW currently calls the execution part of each display routine (via OBEY), and so doesn't go through the normal mechanism for file storing. A small modification has been made so that the routines in the DRAW will be stored if the DRAW is executed inside a STDF, but no checks are made on these routines to see if the priority settings are such that they ought to be obeyed as well.
The modifications required to cause DRAW to allow full execution of the member-routines are likely to be extensive. A second OBEY, calling the actual display routines rather than the execution parts, will be needed, adding a routine with over 70 calls. If another DRAW is encountered, moreover, some form of stack mechanism, similar to the file stack for the sequence list, will be required to allow the recursion. This seems to add a large overhead in space for a feature which may be rarely used.